16th of April 2024 |
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A multiband look at ultraluminous X-ray sources in NGC 7424 |
by Soria et al. |
Soria et al. have presented the results of a multi-band study of the
nearby "grand-design", face-on spiral galaxy NGC 7424 located a little
over 10 Mpc from our Galaxy. Two ultraluminous X-ray sources, dubbed
X-1 and X-2, are detected and studied in detail. Thanks to a more
accurate astrometric solution (based on Australia Telescope Compact
Array and Gaia data), the point-like optical counterpart of X-1, an
isolated B8 supergiant, was able to be identified. In contrast, X-2
is in a star-forming region (about 100 pc × 150 pc), near young
clusters and ionized gas. In addition, a strong, persistent
radio source, with an optical counterpart by no X-ray counterpart
is detected.
NGC 7424 was observed with the ATCA in April 2021 at 5.5 and 9.0 GHz while the array was in a 6 km configuration, providing the highest angular resolution imaging at these frequencies. The image above shows a Gemini-South GMOS image of NGC 7424 with Chandra/ACIS-S contours of the brightest X-ray sources (0.3–7 keV band) overplotted in green. The location of a strong, persistent radio source (R-1) is also labelled. |