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BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220706T150000
DTEND;TZID=Australia/Sydney:20220706T160000
DTSTAMP:20260517T144107
CREATED:20250819T074945Z
LAST-MODIFIED:20250820T032616Z
UID:14972-1657119600-1657123200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Rob Wittenmyer (University of South Queensland)
DESCRIPTION:USQ’s Mount Kent Observatory: Australia’s newest exoplanet machine\n\nAbstract\n\nIn the past five years\, the University of Southern Queensland’s Mount Kent Observatory has undergone a dramatic expansion to become Australia’s leading exoplanet observatory. The MINERVA-Australia telescope array is a partnership between MIT\, UNSW Sydney\, George Mason University\, University of Louisville\, Nanjing University\, University of Texas\, and the University of Florida. It is the only southern hemisphere observatory wholly dedicated to the detailed follow-up of planet candidates from NASA’s Transiting Exoplanet Survey Satellite (TESS)\, and has contributed to the confirmation of 30 planets to date — about 15% of all TESS confirmed planets. I present mass measurements and system parameters for several new planets using MINERVA-Australis radial velocities\, and give preliminary results from our new multi-telescope photometric capability to validate small TESS planet candidates. I also describe our longer-term plans for extended mission science and new large telescopes\, taking advantage of the unique capabilities of this dedicated observatory. \n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-rob-wittenmyer-university-of-south-queensland/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-06072022.jpg
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BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220615T150000
DTEND;TZID=Australia/Sydney:20220615T160000
DTSTAMP:20260517T144107
CREATED:20250819T075210Z
LAST-MODIFIED:20250820T032633Z
UID:14973-1655305200-1655308800@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Marcin Glowacki (Curtin)
DESCRIPTION:MeerKATs\, Lions\, and work with CRAFT\n\nAbstract\n\nIn this talk\, I will present work on a variety of projects. I will begin with the Looking At the Distant Universe with the MeerKAT Array (LADUMA) survey\, among other projects I’ve been involved in with the MeerKAT telescope. Upcoming neutral hydrogen (HI) emission surveys such as LADUMA with SKA Pathfinder telescopes will greatly increase our understanding of galaxy evolution\, especially as a function of redshift. I will highlight the detection of ‘Nkalakatha’\, the first high-redshift OH (hydroxyl) megamaser found through the main emission lines\, and the first scientific result of LADUMA. \n\n Following this\, I will showcase results of baryonic Tully-Fisher relation (BTFR) studies conducted with the cosmological hydrodynamic Simba galaxy simulations. Results from Simba have been compared to observational BTFR studies in the local Universe. By constructing mock HI cubes\, we also make a prediction on whether LADUMA could detect a redshift evolution of the BTFR. Other Simba projects will also be highlighted\, that will complement LADUMA and other SKA precursor science surveys. Lastly\, I will highlight the Commensal Real-time ASKAP Fast Transients (CRAFT) survey\, which I am now working on at Curtin University. CRAFT is currently developing the CRAFT Coherent (CRACO) system\, which will greatly increase the efficiency of detecting and localising fast radio bursts to their host galaxies. \n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-marcin-glowacki-curtin/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/png:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-15062022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220525T150000
DTEND;TZID=Australia/Sydney:20220525T160000
DTSTAMP:20260517T144107
CREATED:20250819T075315Z
LAST-MODIFIED:20250819T075315Z
UID:14974-1653490800-1653494400@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Ron Ekers (CSIRO)
DESCRIPTION:A brief history of the discovery of Sgr A*\n\nAbstract\n\nThe discovery of radio emission from the centre of our galaxy leading up to the EHT image of the SgrA* black hole is a story of discovery\, controversy\, serendipity\, black holes\, Nobel prizes\, mysterious patterns around the galactic centre and now the EHT black hole image magic. The initial discovery of the radio source Sagittarius A and its association with the centre of the Milky Way is a fascinating story\, involving CSIRO-RPL personnel and prominent US and Dutch astronomers. But by “discovery” I do not mean a single event. Contrary to the conventions in science that award prizes\, professional respect and makes press releases\, discovery is a lengthy process involving many actors\, many different kinds of contributions\, and many events over a period of time — 70 years in the case of the galactic centre! I will conclude with a summary of the EHT result and my views on this very difficult analysis. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-ron-ekers-csiro-2/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-25052022.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220518T150000
DTEND;TZID=Australia/Sydney:20220518T160000
DTSTAMP:20260517T144107
CREATED:20250819T075355Z
LAST-MODIFIED:20250819T075355Z
UID:14975-1652886000-1652889600@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Kelly Gourdji (Swinburne)
DESCRIPTION:LOFAR observations of neutron star mergers\n\nAbstract\n\nBoth coherent and incoherent low-frequency radio emission are predicted at various timescales when neutron stars coalesce. In this talk\, I show how the Low-Frequency Array (LOFAR) is being used to catch both fast and slow radio transients related to neutron star mergers. At the earliest timescales\, coherent emission resembling FRBs is predicted by several theoretical models. Testing these models can shed light on the nature of the merger remnant and other important questions\, but requires rapid triggered observations. Here\, I show how we are using LOFAR to trigger on short gamma-ray bursts (SGRBs) detected by Swift\, which have neutron star merger progenitors. In addition to possible prompt emission\, there will be a long-lasting synchrotron afterglow caused by the merger ejecta’s interaction with the ambient medium. The afterglow contains a wealth of information including the geometry and energy of the merger outflow. The biggest challenge associated with detecting the electromagnetic counterpart of gravitational wave (GW) merger events\, however\, is the large uncertainty (tens-hundreds of square degrees) on their locations. Here\, I demonstrate our strategy which applies LOFAR’s high sensitivity and large field of view to search for GW merger radio counterparts. I present results from LOFAR follow-up observations of merger events from the last GW observing run. I also show how the high sensitivity\, large field of view and range of epochs permit us to probe previously unexplored parts of general radio transient phase space. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-kelly-gourdji-swinburne/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-18052022.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220511T150000
DTEND;TZID=Australia/Sydney:20220511T160000
DTSTAMP:20260517T144107
CREATED:20250819T075504Z
LAST-MODIFIED:20250820T032648Z
UID:14976-1652281200-1652284800@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Manisha Caleb (University of Sydney)
DESCRIPTION:Exploring the transient landscape with MeerKAT\n\nAbstract\n\nFast radio bursts (FRBs) have a story which has been told and retold many times over the past few years as they have sparked excitement and controversy since the pioneering discovery in 2007. The FRB class encompasses a number of microsecond-millisecond duration pulses occurring at Galactic to cosmological distances with energies spanning several orders of magnitude. While most FRBs have been observed as singular events\, a small fraction of them have been observed to repeat over various timescales leading to an apparent dichotomy in the population. Though ~50 progenitor model theories have been proposed with the majority involving neutron stars\, no consensus has emerged for their origin(s). However\, with the discovery of an FRB-like pulse from the Galactic magnetar SGR J1935+2154\, magnetar engine models appear to be the current leading favourite. In this talk\, I will present an overview of the field of FRBs and the recent results from the MeerTRAP project at the MeerKAT radio telescope. \n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-manisha-caleb-university-of-sydney/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-11052022.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220427T150000
DTEND;TZID=Australia/Sydney:20220427T160000
DTSTAMP:20260517T144107
CREATED:20250819T075614Z
LAST-MODIFIED:20250819T075615Z
UID:14977-1651071600-1651075200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Emma Ryan-Weber (Swinburne)
DESCRIPTION:The photons that ionized the Universe\n\nAbstract\n\nLess than 1 billion years after the Big Bang the hydrogen in the Universe transitioned from a neutral to ionized state. The details surrounding the Epoch of Reionization are among the biggest unknowns in modern astrophysics. Significant progress has been made in the last 5 years on when the reionization of cosmic hydrogen concluded\, however we are yet to discover exactly how much ionizing radiation escapes from galaxies through to the intergalactic medium. Determining the escape fraction (fesc) of ionizing radiation is key to modelling and understanding this era. I will summarise our team’s effort on three different fronts. 1) The direct detection and characterisation of Lyman-continuum emission from galaxies just after the reionization era; 2) The lack of correlation between oxygen emission lines and Lyman continuum escape fraction; 3) IGM transmission bias and methodology for recovering the posterior probability distribution of fesc. Our observations shows that a small fraction (or during a small fraction of time or viewing angle) of Lyman continuum emitters tend to be high fesc (“on”)\, whereas most galaxies have fesc close to zero (“off”). The complementary theoretical work highlights the limitations of the common practice of assuming average\, smooth IGM transmission functions. To finish\, in a look to the future\, I will introduce our plans to use a new instrument MAVIS (co-led by Australia) to measure the escape fraction of ionizing radiation from redshift 6 galaxies at the conclusion of the Epoch of Reionization. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-emma-ryan-weber-swinburne/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/png:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-27042022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220420T150000
DTEND;TZID=Australia/Sydney:20220420T160000
DTSTAMP:20260517T144107
CREATED:20250819T075948Z
LAST-MODIFIED:20250819T075949Z
UID:14978-1650466800-1650470400@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Abhimanyu Susobhanan (NAOC)
DESCRIPTION:The Indian Pulsar Timing Array 3.5-year Data Release\n\nAbstract\n\nPulsar Timing Arrays (PTAs) are astronomical experiments that aim to detect gravitational waves in the nanohertz frequency regime by observing an ensemble of millisecond pulsars (MSPs). The Indian Pulsar Timing Array (InPTA) experiment\, operational since 2015\, aims to use the unique strengths of the Giant Metrewave Radio Telescope to help detect nanohertz gravitational waves. The wide low-frequency coverage provided by the uGMRT enables very accurate characterization of radio frequency-dependent effects in the pulsar signal\, such as interstellar dispersion and scattering\, which are major sources of noise in PTA experiments. In this talk\, I will provide an overview of the InPTA experiment and present recent results from the upcoming InPTA data release 1\, which includes precise time-of-arrival and dispersion measure estimates for 14 MSPs spanning 3.5 years. This dataset forms the basis of our recent studies and findings\, including the 2021 profile change event in PSR J1713+0747\, the detection of solar coronal mass ejection from DM excess in timing measurements of PSR J2145-0750\, the investigation of scatter broadening in the low-frequency profile of PSR J1643-1224\, and the determination of dispersion measures and ToA residuals in multiple pulsars using the wideband timing technique. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-abhimanyu-susobhanan-naoc/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/png:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-20042022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220406T150000
DTEND;TZID=Australia/Sydney:20220406T160000
DTSTAMP:20260517T144107
CREATED:20250819T080032Z
LAST-MODIFIED:20250819T080032Z
UID:14979-1649257200-1649260800@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Marisa Brienza (University of Bologna)
DESCRIPTION:Insights into the AGN Life-cycle and Feedback from Low Frequency Radio Observations\n\nAbstract\n\nJets from active galactic nuclei (AGN) are a recurrent phenomenon in a galaxy’s lifetime. Understanding their life-cycle is essential for quantifying the energetic impact they have on their surrounding medium. This is in fact a key ingredient driving the thermal evolution of galaxy groups/clusters and\, in turn\, the evolution of galaxies in the universe over cosmic times. In these years the unprecedented sensitivities provided by SKA precursors/pathfinders are significantly pushing forward the study of the jet life-cycle and the jets’ interaction with the external medium. Here I will discuss some recent progress made in this field using observations at MHz-frequencies\, which are especially suited to unveil the oldest populations of particles injected by AGN jets in their surrounding environment. These are allowing us to select new samples of jetted AGN in different phases of their evolution\, as well as follow the interaction/mixing of the AGN jet plasma with the surrounding medium for hundreds of million years. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-marisa-brienza-university-of-bologna/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-06042022.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220323T150000
DTEND;TZID=Australia/Sydney:20220323T160000
DTSTAMP:20260517T144107
CREATED:20250819T080543Z
LAST-MODIFIED:20250819T080544Z
UID:14980-1648047600-1648051200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Christian Reichardt (University of Melbourne)
DESCRIPTION:Searching for New Physics on the last covid-free* continent\n\nAbstract\n\nMeasurements of the polarisation of the cosmic microwave background (CMB) are an important tool to test our understanding of the Universe. Searches for the faint CMB B-mode signals offer the prospect of detecting inflationary gravitational waves on large angular scales and mapping out the large scale distribution of matter in the Universe through CMB lensing on smaller angular scales. The Antarctic plateau\, in addition to being one of the few places isolated enough to avoid covid\, is an exceptional site for microwave astronomy\, and is the home of the South Pole Telescope. I will show recent results from the SPT-3G camera on the South Pole Telescope. I will also say a few words about CMB-S4\, a new experiment being built for first light at the end of the decade. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-christian-reichardt-university-of-melbourne/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/png:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-23032022.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220316T150000
DTEND;TZID=Australia/Sydney:20220316T160000
DTSTAMP:20260517T144107
CREATED:20250819T080622Z
LAST-MODIFIED:20250820T025109Z
UID:14981-1647442800-1647446400@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Charlotte Ward (University of Maryland)
DESCRIPTION:Tracing the first massive black hole seeds and their merger-driven growth with the Zwicky Transient Facility.\n\nAbstract\n\nOver the last 3 years\, the Zwicky Transient Facility (ZTF) has demonstrated the capability of wide-field time-domain surveys to discover the important black hole populations which trace the formation of the first massive black hole seeds and their merger-driven growth. For instance\, our search for off-nuclear active galactic nuclei (AGN) in ZTF revealed 9 supermassive black holes (SMBHs) which may have been ejected from their host galaxy by gravitational wave recoil from SMBH mergers with misaligned spins. Likewise\, our search for variable intermediate mass black holes (IMBHs) in dwarf galaxies found 200 new IMBH candidates\, most of which could not have been found via their spectroscopic signatures alone. Finally\, our study of periodically variable AGN with double-peaked broad emission lines revealed how single AGN can mimic SMBH binaries and mergers. We found these rare black holes amongst large populations of AGN in part by using innovative forward modelling techniques to improve photometric sensitivity and measure the separations between variable objects and their host galaxies. Our work is an exciting precursor to the Legacy Survey of Space and Time which we expect to detect substantially larger populations of recoiling SMBH and IMBH candidates. \nWatch recording\nSlides\n\ncharlotte_ward_colloquiumDownload\n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-charlotte-ward-university-of-maryland/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-16032022.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220309T150000
DTEND;TZID=Australia/Sydney:20220309T160000
DTSTAMP:20260517T144107
CREATED:20250819T081913Z
LAST-MODIFIED:20250820T025013Z
UID:14982-1646838000-1646841600@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Marcus Lower (CSIRO)
DESCRIPTION:A radio-loud magnetar with an identity crisis\n\nAbstract\n\nMagnetars are a rare class of highly magnetised neutron star. They are the primary source of local gamma-ray bursts and are speculated to produce a significant fraction of extragalactic fast radio bursts. Studying the local population of magnetars within the Milky Way is therefore key to understanding these highly energetic objects and the role they play in the transient sky. In this talk\, I will present the initial results of on-going project to monitor a peculiar radio-loud magnetar\, Swift J1818.0-1607\, with Murriyang\, the Parkes 64-m radio telescope. This includes the unusually pulsar-like properties of this object seen in early observations\, and a brief identity crisis in which the neutron star displayed a host of unique behaviour never before seen any other radio pulsar. \nWatch recording\nSlides\n\nMarcus_Lower_colloquiumDownload\n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-marcus-lower-csiro/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-09032022-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20220216T150000
DTEND;TZID=Australia/Sydney:20220216T160000
DTSTAMP:20260517T144107
CREATED:20250819T082323Z
LAST-MODIFIED:20250819T082323Z
UID:14983-1645023600-1645027200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Joe Callingham (ASTRON/Leiden University)
DESCRIPTION:Radio Stars and exoplanets\n\nAbstract\n\nOne key question that astronomy is attempting to answer is whether there are habitable planets around stars other than our Sun. While we have entered an era where identifying nearby exoplanets has become standard\, discerning whether the environmental conditions dictated by the host stars are suitable for life has proved far more elusive. The detection of low-frequency radio emission from an M dwarf or an exoplanet provides a direct probe of extrasolar space weather and the planet’s magnetic field – information crucial for assessing the potential habitability of the planet. In this talk\, I will outline our LOFAR survey of stellar systems\, with a focus on our recent detection of strong\, highly circularly polarised low-frequency radio emission associated with nearby stars – the expected signpost of star-exoplanet interactions. I will discuss how our survey represents the most comprehensive observations of stellar systems at low frequencies\, and the implications of this new population in understanding the magnetosphere of M dwarfs and exoplanetary magnetic fields. I will conclude with our progress in determining the expected periodicity of the radio emission from star-planet interactions. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-joe-callingham-astron-leiden-university-2/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-16022022.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20211215T150000
DTEND;TZID=Australia/Sydney:20211215T160000
DTSTAMP:20260517T144107
CREATED:20250819T082349Z
LAST-MODIFIED:20250820T032713Z
UID:14984-1639580400-1639584000@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Ravi Subrahmanyan (CSIRO)
DESCRIPTION:Towards radio discovery of cosmic dawn\n\nAbstract\n\nAs First Light from the first stars transforms the universe from the dark ages into cosmic dawn\, the history may be traced in redshifted 21-cm from neutral hydrogen in the gas. Efforts to build precision radiometers over the 40-200 MHz band to detect this faint signal are beginning to yield results of significance to the theory\, thus constraining the starlight of the earliest galaxies. I will present the progression in SARAS radiometers that have been deployed in remote sites in India – at the Timbaktu collective\, in the trans-Himalayan plateau and\, most recently\, floated on a remote lake. I will then discuss the impact of the data on the astrophysics of the Epoch of Reionisation and Cosmic Dawn\, our attempt to confirm the EDGES detection\, and the road ahead. \n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-ravi-subrahmanyan-csiro/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-15122021-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20211124T150000
DTEND;TZID=Australia/Sydney:20211124T160000
DTSTAMP:20260517T144107
CREATED:20250819T082748Z
LAST-MODIFIED:20250820T032735Z
UID:14985-1637766000-1637769600@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Jacinta Delhaize (University of Cape Town / SARAO)
DESCRIPTION:Galaxy evolution surveys with MeerKAT: Selected updates from LADUMA and MIGHTEE\n\nAbstract\n\nLADUMA and MIGHTEE are two galaxy evolution surveys well underway with the SKA precursor telescope MeerKAT. LADUMA (HI only) and MIGHTEE (HI and continuum) are both starting to produce exciting new papers\, thanks to MeerKAT’s excellent sensitivity. I will give a brief overview of these surveys and present selected updates. In particular\, I will discuss source finding attempts using SoFiA on early LADUMA data. \n\n I will also summarise the results of our recent paper (Delhaize et al.\, 2021) on the discovery of two giant radio galaxies (GRGs) in MIGHTEE. GRGs are the largest single objects in the Universe and are relatively rare\, with fewer than 850 currently known. Only around 7% of these have sizes greater than 2Mpc\, yet we have detected two such objects within a 1 square degree field in MIGHTEE-COSMOS Early Science observations. These may be the first of a new population to be revealed through surveys like MIGHTEE\, which provide exquisite sensitivity to diffuse\, extended emission. \n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-jacinta-delhaize-university-of-cape-town-sarao/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-24112021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20211110T150000
DTEND;TZID=Australia/Sydney:20211110T160000
DTSTAMP:20260517T144107
CREATED:20250819T101750Z
LAST-MODIFIED:20250819T101751Z
UID:14986-1636556400-1636560000@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Isobel Romero-Shaw (Monash)
DESCRIPTION:An Interview with an Intermediate-Mass Black Hole: Gravitational-Wave Signal GW190521\n\nAbstract\n\nOn the 21st of May\, 2019\, gravitational-wave observatories LIGO and Virgo detected something we had never seen before. The short signal they captured — more of a low-pitched ‘blip’ than a ‘chirp’ — emanated from the creation of an intermediate-mass black hole\, making GW190521 the first direct evidence of the existence of such objects. This intermediate-mass black hole was formed from the merger of two smaller black holes\, at least one of which had a mass that is troublesome to explain through stellar evolution. Pair-instability supernovae are thought to cause a “gap” in the mass distribution of black holes\, such that black holes with masses between 60 and 130 times the mass of the Sun should not exist. The components of GW190521 had masses of about 85 and 65 solar masses — so how did these “forbidden” black holes come into existence? In this talk\, I will present the results of the LIGO—Virgo Collaboration’s analysis of GW190521. I will explain how we can learn a lot about the source from such a short signal\, and discuss potential formation mechanisms for this mysteriously massive binary. Finally\, I will discuss the implications for the population of compact binaries if any of these formation mechanisms are confirmed. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-isobel-romero-shaw-monash/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-10112021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20211103T150000
DTEND;TZID=Australia/Sydney:20211103T160000
DTSTAMP:20260517T144107
CREATED:20250819T101813Z
LAST-MODIFIED:20250819T101813Z
UID:14987-1635951600-1635955200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Laura Driessen (CSIRO)
DESCRIPTION:Commensal searches for variable radio sources with MeerKAT\n\nAbstract\n\nNew wide-field\, sensitive radio instruments are enabling us to search and investigate the dynamic radio sky like never before. Previous untargeted radio searches in the image plane have been limited by small fields of view\, combining observations from mismatched surveys and instruments\, and large gaps between epochs. Now instruments such the MeerKAT\, ASKAP\, the Karl G. Janksy VLA\, LOFAR\, and the MWA are uncovering large samples of dynamic radio sources without performing targeted searches. ThunderKAT is the MeerKAT large science project for searching for and investigating variable and transient radio sources in the image plane\, and has already revealed exciting results on relativistic binaries\, cataclysmic variables and more. A key part of ThunderKAT’s goals is to perform untargeted\, image-plane searches for variable and transient sources. I will present MKT J170456.2-482100\, the first transient discovered with MeerKAT\, and 25 new variable radio sources discovered with MeerKAT in the image-plane. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-laura-driessen-csiro/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/png:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-03112021.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20211027T150000
DTEND;TZID=Australia/Sydney:20211027T160000
DTSTAMP:20260517T144107
CREATED:20250819T101910Z
LAST-MODIFIED:20250819T101911Z
UID:14988-1635346800-1635350400@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Michael Janssen (MPIfR / Radboud University)
DESCRIPTION:The latest results from the Event Horizon Telescope: Zooming into the heart of Centaurus A\n\nAbstract\n\nCentaurus A is the closest radio galaxy to Earth and has been studied extensively as a laboratory for AGN feedback and potential UHECR source after its discovery as one of the first extragalactic radio sources in 1949. I will present the results from our EHT observations of this southern source. Compared to previous VLBI studies\, we have imaged the AGN jet of Cen A at a 16x sharper resolution and 10x higher observing frequency. This allows us to probe the launching region of an extragalactic radio jet on sub-lightday scales. We can directly compare our image to VLBI observations of M87 at a lower frequency\, as both probe the same size scales in terms of gravitational radii. Based on the similarity of these jets\, we show that our observations provide further support for the fundamental plane of black hole activity in an intermediate mass regime. From the location of the resolved radio core in Cen A\, we predict the source’s black hole shadow to be visible at THz frequencies\, which marks Cen A for future high-frequency space VLBI missions. I will conclude with an outlook of our next observational and modeling steps. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-michael-janssen-mpifr-radboud-university/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/EHT-20072021-1.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20211020T150000
DTEND;TZID=Australia/Sydney:20211020T160000
DTSTAMP:20260517T144107
CREATED:20250819T101933Z
LAST-MODIFIED:20250820T023820Z
UID:14989-1634742000-1634745600@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Nithyanandan Thyagarajan (CSIRO)
DESCRIPTION:Towards a General Theory of Closure Invariants in Radio Interferometry\n\nAbstract\n\nRecent “planet-scale” very long baseline interferometry (VLBI) efforts at millimetre wavelengths have resulted in the first detailed images near the event horizon of the supermassive black hole (SMBH) at the centre of M87 by the Event Horizon Telescope (EHT) collaboration. Calibration of the radio signals received by such widely separated VLBI stations is one of the key challenges in the accurate reconstruction of images. Closure phases and amplitudes in co-polar interferometry\, have long provided calibration-independent observables immune to multiplicative\, station-dependent corruptions. Very recently\, “closure traces” for full polarimetric interferometry have been introduced and used in the recent study of the magnetic field structures around the M87 central black hole. So far\, a systematic method for explicitly exhibiting a full set of invariants has still remained unclear. Using the mathematical framework of the gauge theories of particle physics and Lorentz transformations\, I will describe a general formalism\, applicable to interferometer arrays of arbitrary size\, that uses only triangular combinations of correlations as basic building blocks to precisely isolate a complete and independent set of invariants\, and unifies the treatment for all closure invariants\, from which the closure phases and closure amplitudes familiar in co-polar interferometry naturally emerge. These results can find significant applications in ongoing and future (including space-based) observations of SMBHs using the current and the next-generation EHT (ngEHT)\, and more generally\, polarimetric radio interferometry. \nWatch recording\nSlides\n\nNT_ClosureInvariants_CSIRO_SandA_colloquium_20-Oct-2021Download\n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-nithyanandan-thyagarajan-csiro/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-20102021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210929T150000
DTEND;TZID=Australia/Sydney:20210929T160000
DTSTAMP:20260517T144107
CREATED:20250819T102008Z
LAST-MODIFIED:20250820T032752Z
UID:14990-1632927600-1632931200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Sofia Sheikh (Penn. State)
DESCRIPTION:The Breakthrough Listen Signal-of-Interest ‘blc1’: Analysis\, Origin\, and Lessons Learned\n\nAbstract\n\nThe aim of the search for extraterrestrial intelligence (SETI) is to find technologically-capable life beyond Earth through their technosignatures. On 2019-April-29\, the Breakthrough Listen SETI project observed Proxima Centauri with the Parkes “Murriyang” radio telescope. These data contained a narrowband signal with characteristics broadly consistent with a technosignature near 982 MHz (colloquially named ‘blc1’). In this talk\, I will present the discovery and characterization of blc1 in the context of the ubiquity of human-generated radio interference. Briefly: we find that blc1 is not an extraterrestrial technosignature\, but rather an electronically-drifting intermodulation product of local\, time-varying interferers aligned with the observing cadence. We find dozens of instances of radio interference with similar morphologies to blc1 at harmonically-related frequencies to common clock oscillators. These complex intermodulation products highlight the necessity for detailed follow-up of any signal-of-interest. I will end the talk with a discussion of the necessity of signal verification procedures\, and lessons learned from this intriguing case study. \n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-sofia-sheikh-penn-state/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/png:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-29092021.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210915T150000
DTEND;TZID=Australia/Sydney:20210915T160000
DTSTAMP:20260517T144107
CREATED:20250819T102033Z
LAST-MODIFIED:20250819T102034Z
UID:14991-1631718000-1631721600@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Barnali Das (NCRA-TIFR)
DESCRIPTION:What makes a living\, lazy and luminous pulsar\, a.k.a. ‘Main-sequence Radio Pulse emitter’?\n\nAbstract\n\nLiving\, lazy and luminous pulsars are magnetic early-type stars that emit periodic radio pulses\, just like a ‘normal’ pulsar; but rotating with a considerably less angular speed than that for neutron stars. We call such objects as ‘Main-sequence Radio Pulse emitters’ (MRPs). The emission mechanism behind\, the electron cyclotron maser emission (ECME)\, is the same one that also drives coherent radio emission in planets and dwarf stars. The MRPs have been assumed to be exotic objects due to their rarity for a long time (only one such object was discovered between 2000-2015)\, and why this is the case has been a mystery. In my talk\, I will describe an ongoing survey conducted with the updated Giant Metrewave Radio Telescope (uGMRT) in an effort to resolve this issue. I will present the discoveries made so far\, and an unexpected possibility that has emerged from them. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-barnali-das-ncra-tifr/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/png:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-15092021.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210901T150000
DTEND;TZID=Australia/Sydney:20210901T160000
DTSTAMP:20260517T144107
CREATED:20250819T102054Z
LAST-MODIFIED:20250819T102055Z
UID:14992-1630508400-1630512000@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Christene Lynch (ICRAR/Curtin)
DESCRIPTION:The Long-Baseline Epoch of Reionisation Survey\n\nAbstract\n\nOne of the principal systematic constraints on the Epoch of Reionisation (EoR) experiment is the accuracy of the foreground calibration model. Recent results have shown that highly accurate models of extended foreground sources\, and including models for sources in both the primary beam and its sidelobes\, are necessary for reducing foreground power. To improve the source models in the EoR fields observed by the Murchison Widefield Array (MWA)\, we conducted the Long Baseline Epoch of Reionisation Survey. This survey consists of multi-frequency observations\, spanning 104 – 230 MHz\, of the MWA EoR fields and their eight neighbouring fields using the MWA Phase II extended array. These observations provide high-resolution\, (u\,v)-components to compliment the existing (u\,v)-plane sampling of these fields. Additionally\, due to the better imaging capabilities of the MWA Phase II extended array\, this survey improves upon the sensitivity of the GLEAM survey by roughly a factor of 5 in the EoR fields. This talk will present results from the first half of the LoBE survey and discuss the next steps for foreground modelling for the MWA EoR experiment. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-christene-lynch-icrar-curtin/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-01092021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210825T150000
DTEND;TZID=Australia/Sydney:20210825T160000
DTSTAMP:20260517T144107
CREATED:20250819T102147Z
LAST-MODIFIED:20250819T102148Z
UID:14993-1629903600-1629907200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Nichole Barry (University of Melbourne)
DESCRIPTION:Investigating Traditional Radio Astronomy Techniques in an EoR Context\n\nAbstract\n\nDetecting the Epoch of Reionisation is a major directive of the future SKA\, and an active area of research for SKA-precursors including the MWA. However\, measuring the 21cm signal of primordial hydrogen requires a delicate intersection of precision\, sensitivity\, and advanced mathematical techniques. We investigate previous standards of radio astronomy software in order to understand their inherent level of error and to determine requirements for the MWA and subsequently the SKA. \n\n In particular\, interferometers measure millions and millions of visibilities every minute\, which live neither in image space nor fully Fourier space. Thus\, many of our analysis techniques revolve around the use of FFTs and histogramming procedures. However\, given the faint\, spectral nature of the signal we are trying to detect\, we show ways that these traditional techniques fail to reach the required precision. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-nichole-barry-university-of-melbourne/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-25082021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210818T150000
DTEND;TZID=Australia/Sydney:20210818T160000
DTSTAMP:20260517T144107
CREATED:20250819T102205Z
LAST-MODIFIED:20250819T102205Z
UID:14994-1629298800-1629302400@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Shivani Bhandari (CSIRO)
DESCRIPTION:Fast Radio Bursts with the Australian SKA Pathfinder\n\nAbstract\n\nFast radio bursts (FRBs) are amongst the most energetic transients in our Universe\, but despite several plausible models\, their origin remains a mystery. In the absence of multi-wavelength counterparts to extragalactic FRBs\, analyses of their host galaxy environments are presently the most informative path to identifying their progenitor systems. Thanks to recent advances using the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope we can now routinely localise FRBs to the galaxies they originate form\, and in some cases even pinpoint the burst to a region within the galaxy. In addition\, localising FRBs to their host galaxies allows us to use them as probes to trace the ionised gas in galaxy haloes\, large-scale structure and the inter-galactic medium. In this talk\, I will briefly review our current understanding of the FRB phenomena\, highlighting the role of FRB searches and localisation with ASKAP. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-shivani-bhandari-csiro/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-18082021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210721T150000
DTEND;TZID=Australia/Sydney:20210721T160000
DTSTAMP:20260517T144107
CREATED:20250819T102244Z
LAST-MODIFIED:20250819T102245Z
UID:14995-1626879600-1626883200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Danny Price & Marcin Sokolowski (ICRAR / Curtin)
DESCRIPTION:A High-Speed All-Sky Monitor for Fast Radio Bursts and Technosignatures\n\nAbstract\n\nFast Radio Bursts (FRB) are one of the most intriguing transient phenomena discovered in the recent years\, and recently observed down to 100-MHz frequencies. I will present the first southern hemisphere all-sky real-time imaging and radio-transient monitoring system\, implemented on two prototype stations of the low frequency (50–350 MHz) component of the Square Kilometre Array (SKA-Low)\, the Engineering Development Array 2 (EDA2) and Aperture Array Verification System 2 (AAVS2). For the last two years these prototypes have been regularly collecting data to verify their performance against the SKA-Low specifications and simulations\, including making all-sky images every two seconds used for transient searches. The transient identification algorithm used 2-second difference images to find candidates and required their detection in the images from both stations. In approximately 360 hours of data using a single coarse channel (0.926 MHz bandwidth)\, we identified a few episodes of extremely bright pulses from the pulsar PSR B0950+08 and several transients from an unknown object\, which is currently under investigation. We also determined preliminary upper limits on surface density of radio transients at a 2-second timescale. We plan to increase the bandwidth by at least 40 times (to about 40 MHz) and time resolution to 10 ms or better in order to improve the sensitivity by two orders of magnitude and start detecting hundreds of FRBs per year. This upgrade will transform the stations into low-frequency FRB survey machines looking for FRBs and signals from extraterrestrial intelligence in high-resolution all-sky images\, which will pave the way to similar searches with hundreds of SKA-Low stations. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-danny-price-marcin-sokolowski-icrar-curtin/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-21072021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210707T150000
DTEND;TZID=Australia/Sydney:20210707T160000
DTSTAMP:20260517T144107
CREATED:20250819T102351Z
LAST-MODIFIED:20250819T102352Z
UID:14996-1625670000-1625673600@www.atnf.csiro.au
SUMMARY:S&A Colloquium: JinLin Han (NAOC)
DESCRIPTION:The FAST Galactic Plane Pulsar Snapshot survey\n\nAbstract\n\nThe Five-hundred-meter Aperture Spherical radio Telescope (FAST)\, that incorporates an L-band 19-beam receiver with a system temperature of about 20 K\, is the most sensitive radio telescope utilized for discovering pulsars. We designed the snapshot observation mode for a FAST key science project\, the Galactic Plane Pulsar Snapshot (GPPS) survey. The integration time for each pointing is 300 seconds so that the GPPS observations for a cover can be made in 21 minutes. The goal of the GPPS survey is to discover pulsars within the Galactic latitude of ±10deg from the Galactic plane\, and the highest priority is given to the inner Galaxy within ±5deg. \n\nUp to now\, the GPPS survey has discovered 212 pulsars\, including currently the faintest pulsars which cannot be detected by other telescopes\, pulsars with extremely high dispersion measures (DMs) which challenge the currently widely used models for the Galactic electron density distribution\, pulsars coincident with supernova remnants\, 42 millisecond pulsars\, 17 binary pulsars\, some nulling and mode-changing pulsars and rotating radio transients (RRATs). The follow-up observations for confirmation of new pulsars have polarization-signals recorded for polarization profiles of the pulsars. Re-detection of previously known pulsars in the survey data also leads to significant improvements in parameters for 64 pulsars. The GPPS survey discoveries are published and will be updated at http://zmtt.bao.ac.cn/GPPS/. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-jinlin-han-naoc/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-07072021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210616T150000
DTEND;TZID=Australia/Sydney:20210616T160000
DTSTAMP:20260517T144107
CREATED:20250819T102425Z
LAST-MODIFIED:20250819T102426Z
UID:14997-1623855600-1623859200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: James Miller-Jones (ICRAR / Curtin)
DESCRIPTION:Inefficient stellar winds from a massive black hole progenitor in the X-ray binary system Cygnus X-1\n\nAbstract\n\nThe high-mass X-ray binary system Cygnus X-1 contains one of the first known and best-studied black holes. We recently refined the distance to the source using astrometric very long baseline interferometry observations. The new distance implied that the component masses needed to be revised upwards\, with our modelling showing that the system hosts a 21-solar mass black hole. The formation of such a massive black hole in a Galactic environment with roughly solar metallicity challenges existing model prescriptions for the wind mass loss rates from massive stars. I will discuss our new measurements and their consequences for the likely formation and subsequent evolutionary pathway of the black hole\, and touch on their implications for massive star evolution and the formation of gravitational-wave sources. \nWatch recording\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-james-miller-jones-icrar-curtin/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-16062021-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210602T150000
DTEND;TZID=Australia/Sydney:20210602T160000
DTSTAMP:20260517T144107
CREATED:20250819T102456Z
LAST-MODIFIED:20250820T022746Z
UID:14998-1622646000-1622649600@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Michael Busch (Johns Hopkins University)
DESCRIPTION:Revealing the Galactic Dark H2 with OH\n\nAbstract\n\nThe intersection between the atomic and molecular interstellar medium (ISM) is still relatively mysterious. In the past two decades\, indirect gas tracers such as gamma-ray and dust emission have implied the existence of abundant molecular hydrogen (H2) not traced by our canonical molecular tracer\, the CO molecule. This H2 likely lies in diffuse clouds where CO will be not sufficiently collisionally excited or even photodissociated. I will discuss recent efforts in using the OH molecule in emission at 18cm to trace the large-scale Galactic dark H2\, and what we have learned about this previously invisible phase of the diffuse molecular ISM through ultra-sensitive (RMS ~ 1mK) 18cm OH emission surveys with the 100m Green Bank Telescope (GBT). Sensitive OH observations serendipitously revealed an immense amount of dark H2 in the Outer Galaxy in the form of a diffuse disk\, co-spatial with the atomic phase as traced by the HI 21cm line. I will also discuss upcoming GBT projects using the optically thin OH lines as a tool to investigate Galactic structure and present the (preliminary) first detection of thermal OH emission in another Galaxy (M31). \nWatch recording\nSlides\n\nRevealing the Galactic Dark H2 with OHDownload\n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-michael-busch-johns-hopkins-university/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-02062021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210526T150000
DTEND;TZID=Australia/Sydney:20210526T160000
DTSTAMP:20260517T144107
CREATED:20250819T102534Z
LAST-MODIFIED:20250820T022241Z
UID:14999-1622041200-1622044800@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Ray Norris (Western Sydney University / CSIRO)
DESCRIPTION:Indigenous Australian Astronomy and Navigation\n\nAbstract\n\nAboriginal people in Australia have a rich astronomical tradition such as the “Emu in the Sky” constellation of dark clouds\, and stories about the Sun\, Moon\, and stars\, revealing a depth and complexity of pre-contact Aboriginal cultures which are not widely appreciated by outsiders. Not only did they know the sky intimately\, but they were familiar with planetary motions\, tides\, and eclipses. Their songs and stories show that Aboriginal Australians sought to understand their Universe in a similar way to modern science. They used this knowledge of the sky to construct calendars\, songlines\, and other navigational tools\, enabling them to navigate across the country\, trading artefacts and sacred stories. \nWatch recording\nSlides\n\nAboriginalAstronomy_50mins_CASS_2021May26Download\n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-ray-norris-western-sydney-university-csiro/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-26052021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210519T150000
DTEND;TZID=Australia/Sydney:20210519T160000
DTSTAMP:20260517T144107
CREATED:20250819T102603Z
LAST-MODIFIED:20250820T022041Z
UID:15000-1621436400-1621440000@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Lankeswar Dey (TIFR)
DESCRIPTION:Confirming the presence of a supermassive black hole binary in OJ 287 using multi-wavelength observations\n\nAbstract\n\nThe observed quasi-periodic doubly peaked high-brightness flares in the 130-year long optical lightcurve of blazar OJ 287 is best explained by its binary black hole (BBH) central engine model\, where a supermassive secondary black hole (BH) orbits a more massive primary BH in a relativistic eccentric orbit. In this model\, the doubly peaked flares arise due to impacts of the secondary BH with the accretion disk of the primary twice every orbit. This model is successful in predicting the starting time of the last three flares\, and the latest one was observed during August 2019 with the Spitzer space telescope. The observations of these predicted flares strongly suggest the presence of an SMBHB that inspirals due to the emission of nano-Hz gravitational waves (GWs) as the central engine of OJ 287. Additionally\, the high-resolution Very Long Baseline Interferometry (VLBI) observations of OJ 287 reveal that its radio jet’s position angle (PA) exhibits systematic temporal variations. These variations can arise from the precession of the radio jet of OJ 287 due to the binary nature of its central engine. A recent analysis reveals that the BBH central engine model\, primarily developed from the optical observations\, can naturally explain the temporal variations in the radio jet PA of OJ 287\, observed at 86\, 43\, and 15 GHz frequencies. Furthermore\, the ongoing and future Global mm-VLBI Array (GMVA) campaigns on OJ 287 have the potential to firmly establish the validity of our model. These considerations make OJ 287 an excellent candidate for the nascent field of multimessenger nano-Hz GW astronomy\, expected to be inaugurated by the International Pulsar Timing Array (IPTA) consortium during the present decade. \nWatch recording\nSlides\n\nCSIRO OJ 287 seminarDownload\n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-lankeswar-dey-tifr/
CATEGORIES:Colloquia
ATTACH;FMTTYPE=image/jpeg:https://www.atnf.csiro.au/wp-content/uploads/2024/12/Colloq-19052021.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Australia/Sydney:20210512T150000
DTEND;TZID=Australia/Sydney:20210512T160000
DTSTAMP:20260517T144107
CREATED:20250819T102631Z
LAST-MODIFIED:20250820T032816Z
UID:15001-1620831600-1620835200@www.atnf.csiro.au
SUMMARY:S&A Colloquium: Guillaume Drouart (ICRAR / Curtin)
DESCRIPTION:Toward the first sample of radio powerful AGN in the EOR\n\nAbstract\n\nWith the very recent discovery of radio luminous AGN at z>6\, a new window of opportunity is finally opening in the study of the galaxy evolution at the end of the Epoch of Reionization. Our pilot programme in the 60 deg^2 GAMA-09 field uses a new selection technique taking advantage of the large frequency coverage of GLEAM by selecting compact\, steep and curved sources at low-frequency (70-230MHz). Out of four candidates\, one new powerful radio galaxy\, 0856+0224\, is confirmed at z=5.55\, finally overtaking the z=5.2 20 year-old record for distant radio galaxies (albeit just falling short of the new recent z=5.7 record). Interestingly\, 0856+0224 presents similarities with existing z<5 redshift samples\, giving confidence in the success of our selection technique. Our recent progress on a second source\, 0917-0012\, thanks to the extensive multi-wavelength coverage from follow-up observations with ALMA and JVLA\, supplemented with publicly available data\, place this source at a promising z>5. I will also discuss the refinement of our selection technique over the full 1200 deg^2 sky area covered by the ESO VIKING near-infrared survey\, leading to 55 new high-redshift candidates. This sample aims to provide us with the first statistically significant radio luminous active galactic nuclei sample at z > 6.5 during the Epoch of Reionization. The nature of radio selection presents the advantage of being insensitive to orientation-dependent obscuration\, it allows us (i) to study simultaneously the co-evolution of the supermassive black hole and host galaxy and (ii) to enable the study of the IGM through the HI absorption line. \n\nEvent details\nDownload iCal\nCategory\nColloquia
URL:https://www.atnf.csiro.au/event/sa-colloquium-guillaume-drouart-icrar-curtin/
CATEGORIES:Colloquia
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