SDSS J122958.84+000138.0

• Verfasst von: Paudel, Sanjaya [VerfasserIn]
• Verfasst von: Lisker, Thorsten [VerfasserIn]
• Verfasst von: Huxor, Avon P. [VerfasserIn]
• Titel: SDSS J122958.84+000138.0
• Titelzusatz: a compact, optically red galaxy
• Verf.angabe: Sanjaya Paudel, Thorsten Lisker, Avon P. Huxor and Chang H. Ree
• E-Jahr: 2016
• Jahr: 08 December 2016
• Umfang: 9 S.
• Fussnoten: Gesehen am 26.10.2017
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2017
• Band/Heft Quelle: 465(2017), 2, Seite 1950-1958
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/stw2923
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1564792838

Abstract

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.