This pipeline is used for the contstruction of the MaNGA object catalog (MaNGAObj) used in Fu et al. 2018, Steffen et al. 2021, Steffen et al. 2022, and Steffen et al. 2023. The pipeline has the following main steps;
- Cross-match MaNGA fields with SDSS's photometric catalog (PhotObj)
- Clean overdeblended sources from PhotObj
- Add in any missing sources
- Extract spectra from the MaNGA data-cubes for each PhotObj
- Build models for the extracted spectra
- Classify the extracted spectra
- Build a summary catalog
MaNGA_SpecObj.fits contains our visual classifications for the identified objects along with their positions and r-band mangnitudes from SDSS's photometric catalog. The table is organized into the following columns;
| Column | Shape | Description |
|---|---|---|
| PLATEIFU | 15592, | MaNGA Observation ID |
| INDEX | 15592, | Obj Index in IFU (INDEX = 0 is the MaNGA target) |
| RA | 15592, | Right Ascension J2000 (deg) |
| DEC | 15592, | Declination J2000 (deg) |
| TYPE | 15592, | SDSS PhotObj Type |
| PSFMAG_R | 15592, | SDSS PSF r mag |
| PSFMAGERR_R | 15592, | mag error |
| PETROMAG_R | 15592, | SDSS Petro r mag |
| PETROMAGERR_R | 15592, | mag error |
| MODELMAG_R | 15592, | SDSS Model r mag |
| MODELMAGERR_R | 15592, | mag error |
| MAINTARG | 15592, | MaNGA Target Galaxy |
| DIS2OBJ | 15592, | Sep w/ Primary (") |
| ZCLASS | 15592, | Z classification (1=z_corr, 0=z_off, -1=unclass) |
| SCLASS | 15592, | Spectral classification (1=galaxy, 2=BLAGN, 3=star, -1=lowSN, -2=defect) |
MaNGAObj_aper2arc_v1.fits and MaNGAObj_aper2kpc_v1.fits contain positions and derived parameters for all of our identified objects. The two files are identical except that the derived parameters in MaNGAObj_aper2arc_v1.fits are calculated from a 2 arcsecond diameter circular aperture while the derived parameters in MaNGAObj_aper2kpc_v1.fits are calculated from a 2 kpc diameter circular aperture (where the aperture size is calculated from the object's redshift). These tables have the same organization as MaNGA_SpecObj.fits.
Both data tables have the following columns;
| Column | Shape | Description |
|---|---|---|
| RA | 15592, | Right Ascension J2000 (deg) |
| DEC | 15592, | Declination J2000 (deg) |
| SNR | 15592, | Signal-to-noise of the stellar continuum |
| REDSHIFT | 15592, | redshift |
| FLUX | 15592, 2, 17 | Emission line flux (value, Error), (lines) |
| EW | 15592, 17 | Equivalent width (lines) |
| VEL | 15592, 2, 17 | Gas kinematics (value, Error), (lines) |
| SIGMA | 15592, 2, 17 | Gas velocity dispersion (value, Error), (lines) |
| H3 | 15592, 2, 17 | 3rd moment of the Gauss-Hermite series (value, Error), (lines) |
| H4 | 15592, 2, 17 | 4th moment of the Gauss-Hermite series (value, Error), (lines) |
| AON | 15592, 17 | Amplitude over noise for 17 emission lines (lines) |
| SIGMA_OBS | 15592, 17 | noise calculated from residual spectrum (lines) |
| EBMV | 15592, 2 | intrinsic reddening and err (value, error) |
| KINSTAR | 15592, 2, 4 | stellar kinematics (Value, error), (velocity, velocity dispersion, H3, H4) |
| WEIGHTS | 15592, 2, 78 | weights of SSP templates in units of 1e-30 (value, error), (weights) |
| M_STAR | 15592, 2, 78 | stellar mass (value, error), (weights) |
| CHI2PPXF | 15592, | Chi^2/DOF from PPXF |
| CHI2NU | 15592, | Chi^2/DOF from SPFIT |
The extracted emission lines are given below, the index refers to its position in the above tables.
| Index | Linename | Wavelength (A) |
|---|---|---|
| 0 | OII | 3730 |
| 1 | NeIII | 3870 |
| 2 | NeIII | 3969 |
| 3 | Hg | 4342 |
| 4 | OIII | 4364 |
| 5 | HeII | 4687 |
| 6 | Hb | 4863 |
| 7 | OIII | 5008 |
| 8 | NI | 5199 |
| 9 | NaI | 5892 |
| 10 | NaI | 5898 |
| 11 | OI | 6302 |
| 12 | Ha | 6565 |
| 13 | NII | 6585 |
| 14 | SII | 6718 |
| 15 | SII | 6733 |
| 16 | ArIII | 7138 |
The files can be accessed in Python using the package, AstroPy. The table may be opened and columns may be called with the following example code block.
from astropy.io import fits
mangaobj = fits.open('/path_to_file/MaNGA_SpecObj_v1.fits')
obj = mangaobj[1].data
mangaspfit = fits.open('/path_to_file/MaNGAObj_aper2kpc_v1.fits')
dat = mangaspfit[1].data
# Right ascensions and declinations
ra = obj['RA']
Dec = obj['DEC']
# ZCLASS and SCLASS
zclass = obj['zclass']
sclass = obj['sclass']
# plateifus with BLAGN whose redshifts are similar to the MaNGA target
ix = (zclass == 1)&(sclass == 2)
plateifus = obj['plateifu'][ix]
# H-alpha flux and error
flux = dat['flux']
halpha = flux[:,0,12]
halpha_err = flux[:,1,12]
# H-alpha flux of galaxies whose redshifts are similar to the MaNGA target
iy = (zclass == 1)&(sclass == 1)
halpha = flux[iy,0,12]