Schema of LAMOST Quasar Catalog

2019-01-10 14:22

2019-01-10 14:53

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The content and description of each column of LAMOST full quasar catalog are nearly the same as in Ai et al. (2016); Dong et al. (2018) and Yao et al. (2019), and is also provided below. Since the LAMOST quasar catalogs are published seperately, the values in some columns in one catalog may be unavailable in others. The value is set to $-9999$ in this case, unless mentioned otherwise.

Column Name Data Format Description
ObsID Integer Unique Spectra ID
Designation String LAMOST designation hhmmss.ss+ddmmss (J2000)
RA Double Right ascension in decimal degrees (J2000)
Dec Double Declination in decimal degrees (J2000)
MJD Long Modified Julian Day of observation
planID String Spectroscopic plan name
spID Long Spectrograph identification
fiberID Long Spectroscopic fiber number
z_vi Double Redshift by visual inspection
zWarning Integer Flag of redshift from visual inspection. 1 = not robust.
Mi_z2 Double Absolute $i$-band magnitude. -corrected to $z=2$ following Richards et al. (2006)
NspecOBS Integer Number of spectroscopic observations for the quasar. When there are more than one observation for the object, the line properties are obtained from only one of the observations in which the fiber pointing position is nearest to the position in the input quasar candidate catalog
SNR_spec Double Median S/N per pixel in the wavelength regions of [4000-5700]Å and [6200, 9000]Å.
BAL_flag Integer Flag of broad absorption features. BAL_FLAG=1 indicates broad absorption features are present.
FWHM_BROAD_HA Double FWHM of broad H$\alpha$ in units of km/s
EW_BROAD_HA Double Equivalent width of broad H$\alpha$ in units of Å
FWHM_NARROW_HA Double FWHM of narrow H$\alpha$ in units of km/s
EW_NARROW_HA Double Equivalent width of broad H$\alpha$ in units of Å
EW_NII_6585 Double equivalent width of [NII]6563 in units of Å
EW_SII_6718 Double equivalent width of [SII]6718 in units of Å
EW_SII_6732 Double equivalent width of [SII]6732 in units of Å
EW_FE_HA Double Rest-frame equivalent width of iron emissions in 6000-6500 Å
LINE_NPIX_HA Long Number of good pixels for the spectrum in region of rest-frame 6400-6765 Å
LINE_MED_SN_HA Double Median S/N per pixel for the spectrum in region of rest-frame 6400-6765 Å
LINE_FLAG_HA Integer Flag indicates reliability of the emission line fitting results in H$\alpha$ region upon visual inspections. 0=reliable; -1=unreliable. This value is set to be −9999 if H$\alpha$ is not measured due to lack of good pixels in the fitting wavelength region.
FWHM_BROAD_HB Double FWHM of broad H$\beta$ in units of km/s
EW_BROAD_HB Double Equivalent width of broad H$\beta$ in units of Å
FWHM_NARROW_HB Double FWHM of narrow H$\beta$ in units of km/s
EW_NARROW_HB Double Equivalent width of narrow H$\beta$ in units of Å
FWHM_OIII_5007 Double FWHM of [OIII]5007 in units of km/s
EW_OIII_5007 Double Equivalent width of [OIII]5007 in units of Å
EW_FE_HB Double Rest-frame equivalent width of iron emissions in 4685-4435 Å
LINE_NPIX_HB Long Number of good pixels for the spectrum in region of rest-frame 4750-4950 Å.
LINE_MED_SN_HB Double Median S/N per pixel for the spectrum in region of rest-frame 4750-4950 Å.
LINE_FLAG_HB Integer Flag indicates reliability of the emission line fitting results in H$\beta$ region upon visual inspections. 0=reliable; -1=unreliable. This value is set to be −9999 if H$\beta$ is not measured due to lack of good pixels in the fitting wavelength region.
FWHM_MGII Double FWHM of the total MgII emission line in units of km/s
EW_MGII Double Equivalent width of the total MgII emission line in units of Å
FWHM_BROAD_MGII Double FWHM of the total broad MgII emission line in units of km/s
EW_BROAD_MGII Double Equivalent width of the total broad MgII emission line in units of Å
FWHM_BROAD_MGII_2796 Double FWHM of the broad MgII$\lambda$2796 emission line in units of km/s.
FWHM_NARROW_MGII_2796 Double FWHM of the narrow MgII$\lambda$2796 emission line in units of km/s.
EW_FE_MGII Double Rest-frame equivalent width of iron emissions in 2200-3090 Å.
LINE_NPIX_MGII Long Number of good pixels for the spectrum in region of rest-frame 2700-2900 Å.
LINE_MED_SN_MGII Double Median S/N per pixel for the spectrum in region of rest-frame 2700-2900 Å.
LINE_FLAG_MGII Integer Flag indicates reliability of the emission line fitting results in MgII region upon visual inspections. 0=reliable; -1=unreliable. This value is set to be −9999 if MgII is not measured due to lack of good pixels in the fitting wavelength region.
FWHM_CIV Double FWHM of the total CIV emission line in units of km/s.
EW_CIV Double Equivalent width of the total CIV emission line in units of Å
FWHM_BROAD_CIV Double FWHM of the broad CIV emission line in units of km/s.
EW_BROAD_CIV Double Equivalent width of the broad CIV emission line in units of Å
FWHM_NARROW_CIV Double FWHM of the narrow CIV emission line in units of km/s.
EW_NARROW_CIV Double Equivalent width of the narrow CIV emission line in units of Å
LINE_NPIX_CIV Long Number of good pixels for the spectrum in region of rest-frame 1500-1600 Å
LINE_MED_SN_CIV Double Median S/N per pixel for the spectrum in region of rest-frame 1500-1600 Å
LINE_FLAG_CIV Integer Flag indicates reliability of the emission line fitting results in C IV region upon visual inspections. 0=reliable; -1=unreliable. This value is set to be −9999 if C IV is not measured due to lack of good pixels in the fitting wavelength region.
ALPHA_LAMBDA_1 Double Wavelength power-law index, ${\alpha }_{\lambda }$, from $\sim$ 1300 to 4661 Å.
ALPHA_LAMBDA_2 Double Wavelength power-law index, ${\alpha }_{\lambda }$, redward of 4661 Å.
MODEL_PHOT_REDCHI2 Double Reduced chi-square in SDSS photometry modeling. −9999 if not fitted.
LOGL5100 Double Monochromatic luminosities at 5100 Å.
LOGL3000 Double Monochromatic luminosities at 3000 Å.
LOGL1350 Double Monochromatic luminosities at 1300 Å.
LOGBH_HB Double Virial black hole masses (in ${M}_{\odot }$) based on Hβ.
LOGBH_MGII Double Virial black hole masses (in ${M}_{\odot }$) based on MgII.
LOGBH_CIV Double Virial black hole masses (in ${M}_{\odot }$) based on C IV.

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