Journal article
SDSS IV MaNGA: Discovery of an Hα Blob Associated with a Dry Galaxy Pair—Ejected Gas or a “Dark” Galaxy Candidate?
The Astrophysical journal, Vol.837(1), p.32
2017
DOI: 10.3847/1538-4357/837/1/32
Abstract
We report the discovery of a mysterious giant Hα blob that is ∼8 kpc away from the main MaNGA target 1-24145, one component of a dry galaxy merger, and has been identified in the first-year SDSS-IV MaNGA data. The size of the Hα blob is ∼3–4 kpc in radius, and the Hα distribution is centrally concentrated. However, there is no optical continuum counterpart in the deep broadband images reaching ∼26.9 mag arcsec−2 in surface brightness. We estimate that the masses of the ionized and cold gases are 3.3 10 ´ 5 M and <1.3 10 ´ 9 M, respectively. The emission-line ratios indicate that the Hα blob is photoionized by a combination of massive young stars and AGNs. Furthermore, the ionization line ratio decreases from MaNGA 1-24145 to the Hα blob, suggesting that the primary ionizing source may come from MaNGA 1-24145, likely a low-activity AGN. Possible explanations for this Hα blob include the AGN outflow, the gas remnant being tidally or ram-pressure stripped from MaNGA 1-24145, or an extremely low surface brightness galaxy. However, the stripping scenario is less favored according to galaxy merger simulations and the morphology of the Hα blob. With the current data, we cannot distinguish whether this Hα blob is ejected gas due to a past AGN outburst, or a special category of “ultra-diffuse galaxy” interacting with MaNGA 1-24145 that further induces the gas inflow to fuel the AGN in MaNGA 1-24145.
Details
- Title: Subtitle
- SDSS IV MaNGA: Discovery of an Hα Blob Associated with a Dry Galaxy Pair—Ejected Gas or a “Dark” Galaxy Candidate?
- Creators
- Lihwai LinJing-Hua LinChin-Hao HsuHai FuSong HuangSebastián F SánchezStephen GwynJoseph D GelfandEdmond CheungKaren MastersSébastien PeiraniWiphu RujopakarnDavid V StarkFrancesco BelfioreM. S BothwellKevin BundyAlex HagenLei HaoShan HuangDavid LawCheng LiChris LintottRoberto MaiolinoAlexandre Roman-LopesWei-Hao WangTing XiaoFangting YuanDmitry BizyaevElena MalanushenkoNiv DroryJ. G Fernandez-Trincado - Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213)Zach PaceKaike PanDaniel Thomas
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.837(1), p.32
- DOI
- 10.3847/1538-4357/837/1/32
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Publisher
- Institute of Physics (IOP)
- Language
- English
- Date published
- 2017
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199937202771
Metrics
7 Record Views