Table information for 'lamost6.medres'

General

Table Description: Metadata of LAMOST DR6 medium resolution spectra. This table is only used to feed the ssa_mrs view; use that to query data in this table.

This table is not available for ADQL queries and through the TAP endpoint.

Resource Description: LAMOST, the The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (or Guoshoujing Telescope) is an instrument tailored for producing large number of optical medium- and low-resolution spectra. Here, we publish both the medium (MRS) and low (LRS) resolution spectra from Data Release 6, http://dr6.lamost.org/v2/, to the Virtual Observatory.

For a list of all services and tables belonging to this table's resource, see Information on resource 'LAMOST DR6 Spectra'

Citing this table

This table has an associated publication. If you use data from it, it may be appropriate to reference http://dr6.lamost.org/v2/ either in addition to or instead of the service reference.

To cite the table as such, we suggest the following BibTeX entry:

@MISC{vo:lamost6_medres,
  year=2020,
  title={{LAMOST} DR6 Spectra},
  author={National Astronomical Observatories of the Chinese Academy of Sciences},
  url={https://dc.zah.uni-heidelberg.de/tableinfo/lamost6.medres},
  howpublished={{VO} resource provided by the {GAVO} Data Center}
}

Guoshoujing Telescope (the Large Sky Area Multi-Object Fiber Spectroscopic Telescope LAMOST) is a National Major Scientific Project built by the Chinese Academy of Sciences. Funding for the project has been provided by the National Development and Reform Commission. LAMOST is operated and managed by the National Astronomical Observatories, Chinese Academy of Sciences.

Please also see the LAMOST Data Policy.

Columns

Sorted alphabetically. [Sort by DB column index]

NameTable Head DescriptionUnitUCD
accref Product key Access key for the data N/A meta.ref.url
accsize File size Size of the data in bytes byte VOX:Image_FileSize
bad_b B bad? 1 if this is a problematic B spectrum. N/A meta.code
bad_r R bad? 1 if this is a problematic R spectrum. N/A meta.code
coadd Coadd? 1 if this is a co-added spectrum N/A meta.code
dec Target Dec ICRS declination for this object from input catalogue deg pos.eq.dec;meta.main
dec_obs Fiber Dec ICRS declination of the fiber pointing deg pos.eq.dec
designation Target Target Designation (IAU style) N/A meta.id
embargo Embargo ends Date the data will become/became public yr N/A
fiberid Fiber Identifier of the fiber used to take the source spectrum N/A meta.id;instr
fibermask Fiber prob Bitmask for fiber problems. See note for the meaning for the bits. [Note fib] N/A meta.code.qual
fibertype Fiber Fiber Type of target (one of Obj, Sky, F-std, Unused, PosErr, Dead) N/A meta.code;instr
mag_arr Mags. An array of derived magnitudes. See mag_types for the bands these magnitudes are intended for. N/A phot.mag
magtype Mag.Type Designation of the bands of the magnitudes in mag_arr; this is not easy to parse by a machine, sorry. N/A meta.code
mime Type MIME type of the file served N/A meta.code.mime
mobsid Mobsid Unique identifier for the medium resolution spectrum (most of these have multiple observations and include a coadded spectrum). N/A meta.id;meta.main
objtype Ob. type Object type: star, k2star, fs, rvcandi, gal N/A meta.code.class
obsid Obsid Unique identifier for the observation; LAMOST observations typically result in multiple spectra. N/A meta.id;obs
offset_v Offset Offset of the observation from the target coordinate (these are added for bright objects to prevent saturation). arcsec instr.offset
owner Owner Owner of the data N/A N/A
planid Plan Identifier of the observation plan N/A meta.id;obs.proposal
ra Target RA ICRS right ascension for this object from input catalogue deg pos.eq.ra;meta.main
ra_obs Fiber RA ICRS right ascension of the fiber pointing (can be different from ra for bright sources). deg pos.eq.ra
rv_b0 RV b0 Radial velocity estimated from the B spectrum after continuum removal. km/s spect.dopplerVeloc
rv_b0_err Err. RV b0 Error in rv_b0. km/s stat.error;spect.dopplerVeloc
rv_b1 RV b1 rv_b0 after zero-point correction km/s spect.dopplerVeloc
rv_b1_err Err. RV b1 Error in rv_b1. km/s stat.error;spect.dopplerVeloc
rv_b_flag b ? Flag for RV extraction in the b band: 0 – no anomalies; 1 – too many bad pixels; 2 – radial velocity in excess of 450 km/s; 3 – low similarity with best-matched template. N/A meta.code.qual
rv_br0 RV br0 Radial velocity estimated from the B and R spectra after continuum removal. km/s spect.dopplerVeloc
rv_br0_err Err. RV br0 Error in rv_br0. km/s stat.error;spect.dopplerVeloc
rv_br1 RV br1 rv_br0 after zero-point correction km/s spect.dopplerVeloc
rv_br1_err Err. RV br1 Error in rv_br1. km/s stat.error;spect.dopplerVeloc
rv_br_flag br ? Flag for RV extraction in the br band: 0 – no anomalies; 1 – too many bad pixels; 2 – radial velocity in excess of 450 km/s; 3 – low similarity with best-matched template. N/A meta.code.qual
rv_lasp0 RV lasp0 Radial velocity estimated from the LAMOST stellar parameter pipeline. km/s spect.dopplerVeloc
rv_lasp0_err Err. RV lasp0 Error in rv_lasp0. km/s stat.error;spect.dopplerVeloc
rv_lasp1 RV lasp1 rv_lasp0 after zero-point correction km/s spect.dopplerVeloc
rv_lasp1_err Err. RV lasp1 Error in rv_lasp1. km/s stat.error;spect.dopplerVeloc
rv_r0 RV r0 Radial velocity estimated from the R spectrum after continuum removal. km/s spect.dopplerVeloc
rv_r0_err Err. RV r0 Error in rv_r0. km/s stat.error;spect.dopplerVeloc
rv_r1 RV r1 rv_r0 after zero-point correction km/s spect.dopplerVeloc
rv_r1_err Err. RV r1 Error in rv_r1. km/s stat.error;spect.dopplerVeloc
rv_r_flag r ? Flag for RV extraction in the r band: 0 – no anomalies; 1 – too many bad pixels; 2 – radial velocity in excess of 450 km/s; 3 – low similarity with best-matched template. N/A meta.code.qual
spid SG id Identifier of the Spectragraph that took the source spectrum. N/A meta.id;instr
ssa_dateObs Date Obs. Midpoint of exposure (MJD) d time.epoch
ssa_location Location ICRS location of aperture center deg pos.eq
ssa_region Coverage Rough coverage based on location and aperture. N/A pos.outline;obs.field
ssa_snr SNR Median signal to noise ratio over all pixel, computed as flux/sqrt(variance) N/A stat.snr
ssa_specend Band end Upper value of spectral coordinate m em.wl;stat.max
ssa_specres Spec. Res. Resolution (in meters of wavelength) on the spectral axis m spect.resolution;em.wl
ssa_specstart Band start Lower value of spectral coordinate m em.wl;stat.min
target_comment Comment Various comments (e.g., an external target id). N/A meta.note

Columns that are parts of indices are marked like this.

Other

The following services may use the data contained in this table:

VOResource

VO nerds may sometimes need VOResource XML for this table.

Notes

Note fib

Meaning of the bits in fibermask (note: while upstream counts bits from 1, we count bits from 0):

Bit Meaning
0 Fiber not allotted
1 Bad trace from the TRACECENTER routine
2 Low counts in flat field
3 Bad arc solution
4 <10% pixels are bad on the CCD
5 <10% pixels are saturated
6 Whopping fiber
7 Near a whopping fiber
8 Sky fiber shows extreme residuals