Schema of LAMOST Quasar Catalog

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 $α$ in units of km/s
EW_BROAD_HA	Double	Equivalent width of broad H $α$ in units of Å
FWHM_NARROW_HA	Double	FWHM of narrow H $α$ in units of km/s
EW_NARROW_HA	Double	Equivalent width of broad H $α$ 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 $α$ region upon visual inspections. 0=reliable; -1=unreliable. This value is set to be −9999 if H $α$ is not measured due to lack of good pixels in the fitting wavelength region.
FWHM_BROAD_HB	Double	FWHM of broad H $β$ in units of km/s
EW_BROAD_HB	Double	Equivalent width of broad H $β$ in units of Å
FWHM_NARROW_HB	Double	FWHM of narrow H $β$ in units of km/s
EW_NARROW_HB	Double	Equivalent width of narrow H $β$ 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 $β$ region upon visual inspections. 0=reliable; -1=unreliable. This value is set to be −9999 if H $β$ 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 $λ$ 2796 emission line in units of km/s.
FWHM_NARROW_MGII_2796	Double	FWHM of the narrow MgII $λ$ 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, $α_{λ}$ , from $\sim$ 1300 to 4661 Å.
ALPHA_LAMBDA_2	Double	Wavelength power-law index, $α_{λ}$ , 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 $M_{⊙}$ ) based on Hβ.
LOGBH_MGII	Double	Virial black hole masses (in $M_{⊙}$ ) based on MgII.
LOGBH_CIV	Double	Virial black hole masses (in $M_{⊙}$ ) based on C IV.