SDSS J122958.84+000138.0: a compact, optically red galaxy
We report a new compact galaxy, SDSS J122958.84+138.0 (SDSS J1229+0001), which has unique morphological and stellar population properties that are rare in observations of the nearby Universe. SDSS J1229+0001 has an r-band absolute magnitude (Mr) and half-light radius (Rh) of −17.75 mag and 520 pc, r...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article (Journal) |
| Language: | English |
| Published: |
08 December 2016
|
| In: |
Monthly notices of the Royal Astronomical Society
Year: 2017, Volume: 465, Issue: 2, Pages: 1950-1958 |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stw2923 |
| Online Access: | Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1093/mnras/stw2923
|
| Author Notes: | Sanjaya Paudel, Thorsten Lisker, Avon P. Huxor and Chang H. Ree |
| Summary: | We report a new compact galaxy, SDSS J122958.84+138.0 (SDSS J1229+0001), which has unique morphological and stellar population properties that are rare in observations of the nearby Universe. SDSS J1229+0001 has an r-band absolute magnitude (Mr) and half-light radius (Rh) of −17.75 mag and 520 pc, respectively. Located in a fairly low-density environment, morphologically it is akin to a typical early-type galaxy as it has a smooth appearance and red colour. However, interestingly, it possesses centrally concentrated star-forming activity with a significant amount of dust. We present an analysis of its structural and stellar population properties using archival images and VLT/FORS2 spectroscopy. An analysis of the UKIDSS H-band image shows that the observed light distribution is better fitted with a two-component Sérsic function with inner and outer component effective radii of 190 and 330 pc, respectively. The overall half-light radius measured in the H band is much smaller compared to optical, i.e. 290 pc. We prepared a spectral energy distribution from optical to far-infrared and interpret it to derive the star-formation rate, dust mass and stellar mass. We find that SDSS J1229+0001 has dust mass Mdust = 5.1 × 105 M⊙ with a dust-to-stellar mass ratio log (Mdust/M*) = −3.5. While the observed stellar population properties are - to some extent - like those of a typical S0 galaxy, a unified view from stellar population and structural properties may suggest that SDSS J1229+0001 is a smoking gun example of a compact early-type galaxy in formation. |
|---|---|
| Item Description: | Gesehen am 26.10.2017 |
| Physical Description: | Online Resource |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stw2923 |