SDSS-IV MaNGA PyMorph Photometric and Deep Learning Morphological Catalogues and implications for bulge properties and stellar angular momentum
Abstract
We describe the Sloan Digital Sky Survey IV (SDSS-IV) MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) PyMorph Photometric (MPP-VAC) and MaNGA Deep Learning Morphology (MDLM-VAC) Value Added Catalogues. The MPP-VAC provides photometric parameters from Sérsic and Sérsic + Exponential fits to the 2D surface brightness profiles of the MaNGA Data Release 15 (DR15) galaxy sample. Compared to previous PYMORPH analyses of SDSS imaging, our analysis of the MaNGA DR15 incorporates three improvements: the most recent SDSS images; modified criteria for determining bulge-to-disc decompositions; and the fits in MPP-VAC have been eye-balled, and re-fit if necessary, for additional reliability. A companion catalogue, the MDLM-VAC, provides Deep Learning-based morphological classifications for the same galaxies. The MDLM-VAC includes a number of morphological properties (e.g. a TType, and a finer separation between elliptical and S0 galaxies). Combining the MPP- and MDLM-VACs allows to show that the MDLM morphological classifications are more reliable than previous work. It also shows that single-Sérsic fits to late- and early-type galaxies are likely to return Sérsic indices of n ≤ 2 and ≥4, respectively, and this correlation between n and morphology extends to the bulge component as well. While the former is well known, the latter contradicts some recent work suggesting little correlation between n-bulge and morphology. Combining both VACs with MaNGA's spatially resolved spectroscopy allows us to study how the stellar angular momentum depends on morphological type. We find correlations between stellar kinematics, photometric properties, and morphological type even though the spectroscopic data played no role in the construction of the MPP- and MDLM-VACs.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2019
- DOI:
- 10.1093/mnras/sty3135
- arXiv:
- arXiv:1811.02580
- Bibcode:
- 2019MNRAS.483.2057F
- Keywords:
-
- galaxies: fundamental parameters;
- galaxies: photometry;
- galaxies: structure;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 22 pages, 30 figures and 4 tables. Accepted for publication in MNRAS. The MPP-VAC and MDLM-VAC are available online at https://www.sdss.org/dr15/data_access/value-added-catalogs/manga-pymorph-dr15-photometric-catalog and https://www.sdss.org/dr15/data_access/value-added-catalogs/manga-morphology-deep-learning-dr15-catalog