PHL 6625: A Minor Merger-associated QSO Behind NGC 247
- Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)
- Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)
- Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100087 (China)
- National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China)
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States)
- Center for Astrophysics, Tsinghua University, Beijing 100084 (China)
PHL 6625 is a luminous quasi-stellar object (QSO) at z = 0.3954 located behind the nearby galaxy NGC 247 ( z = 0.0005). Hubble Space Telescope observations revealed an arc structure associated with it. We report on spectroscopic observations with the Very Large Telescope and multiwavelength observations from the radio to the X-ray band for the system, suggesting that PHL 6625 and the arc are a close pair of merging galaxies, instead of a strong gravitational lens system. The QSO host galaxy is estimated to be (4–28) × 10{sup 10} M {sub ☉} and the mass of the companion galaxy is estimated to be M {sub *} = (6.8 ± 2.4) × 10{sup 9} M {sub ☉}, suggesting that this is a minor merger system. The QSO displays typical broad emission lines, from which a black hole mass of about (2–5) × 10{sup 8} M {sub ☉} and an Eddington ratio of about 0.01–0.05 can be inferred. The system represents an interesting and rare case where a QSO is associated with an ongoing minor merger, analogous to Arp 142.
- OSTI ID:
- 22663551
- Journal Information:
- Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 841; ISSN ASJOAB; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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