A T N F    D a i l y    A s t r o n o m y    P i c t u r e

7th of May 2015
Dwarf galaxy velocity fields
by Bärbel Koribalski (CASS)
The 21-cm spectral line of hydrogen (HI) traces the cold atomic hydrogen gas in galaxies, which typically extends well beyond their stellar disks. The HI velocity fields shown in the image above are for two nearby dwarf galaxies, ESO223-G009 (left) and ESO215-G?009 (right), observed as part of the Local Volume HI Survey (LVHIS). The near circular HI gas distributions of galaxies suggest nearly face-on orientations, but the two velocity fields tell a different story. Both galaxies are warped, ie. their disk inclination and position angles vary with radius. The origin of warps is still a topic of investigation.

<<   |   archive   |   about   |   today   *   ATNF   |   Parkes   |   ATCA   |   Mopra   |   VLBI   |   ASKAP   |   >>