The location of an active nucleus and a shadow of a tidal tail in the ULIRG Mrk 273
Abstract
Analysis of data from the Chandra X-ray Observatory for the double nucleus ULIRG Mrk 273 reveals an absorbed hard X-ray source coincident with the southwest nucleus, implying that this unresolved, near-infrared source is where an active nucleus resides, while the northern nuclear region contains a powerful starburst that dominates the far infrared luminosity. There is evidence of a slight image extension in the 6-7 keV band, where an Fe K line is present, towards the northern nucleus. A large-scale, diffuse emission nebula detected in soft X-rays contains a dark lane that spatially coincides with a high surface-brightness tidal tail extending ~50 arcsec (40 kpc) to the south. The soft X-ray source is likely located behind the tidal tail, which absorbs X-ray photons along the line of sight. The estimated column density of cold gas in the tidal tail responsible for shadowing the soft X-rays is NH ≥ 6 × 1021 cm -2, consistent with the tidal tail having an edge-on orientation.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 2011
- DOI:
- 10.1051/0004-6361/201015872
- arXiv:
- arXiv:1101.3659
- Bibcode:
- 2011A&A...528A.137I
- Keywords:
-
- galaxies: active;
- X-rays: galaxies;
- galaxies: individual: Mrk 273;
- infrared: galaxies;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- Accepted for publication in A&