This table is available for ADQL queries and through the TAP endpoint.
Resource Description:
For a list of all services and tables belonging to this table's resource, see Information on resource 'Parameters of 220 million stars from Gaia BP/RP (XP) spectra'
This table has an associated publication. If you use data from it, it may be appropriate to reference 2023arXiv230303420Z (ADS BibTeX entry for the publication) either in addition to or instead of the service reference.
To cite the table as such, we suggest the following BibTeX entry:
@MISC{vo:xpparams_main, year=2023, title={Parameters of 220 million stars from Gaia BP/RP (XP) spectra}, author={Zhang, Xiangyu and Green, Gregory M. and Rix, Hans-Walter}, url={https://dc.zah.uni-heidelberg.de/tableinfo/xpparams.main}, howpublished={{VO} resource provided by the {GAVO} Data Center} }
As an example of what one can do with this data, consider the following ADQL query to generate an all-sky extinction map for stars at a distance between 400 pc and 600 pc:
select source_id/140737488355328 as hpx, avg(ext) as meanext from xpparams.main where mod_parallax between 1.67 and 2.5 and quality_flags < 8 and mod_parallax/err_mod_parallax > 5 and err_ext < 0.2 group by hpx
This exploits the fact that Gaia source ids can be converted to HEALPixes to produce a map and shows how to do useful quality cuts that allow relatively careless use of the data.
If you use TOPCAT to execute this on the GAVO DC TAP service (select Asynchronous mode and make sure you set Max Rows to something more than 50000, because that is how many pixels our map will have), you can do a sphere plot, then add a Healpix control. In it, select the table resulting from this query, manually set the HEALPix level to 6 and configure the Axis to Aitoff projection in the Galactic system to arrive at a plot like this:
Try the following query yielding data on Omega Cen and illustrating how to match with the local Gaia DR3 catalogue in order to constrain proper motions:
SELECT xpp.*, g.pmra, g.pmdec, g.phot_g_mean_mag, g.phot_bp_mean_mag, g.phot_rp_mean_mag FROM xpparams.main as xpp JOIN gaia.edr3lite as g USING (source_id) WHERE distance(xpp.ra, xpp.dec, 201.697, -47.479472)<0.5 AND distance(g.pmra, g.pmdec, -3.24, -6.73)<1.25 AND xpp.quality_flags < 8 AND xpp.mod_parallax/xpp.err_mod_parallax > 5. AND xpp.feh_confidence > 0.5 AND xpp.err_fe_h < 0.2
Again in TOPCAT, try a 3d plot of RA, Dec and 1/mod_parallax. You will want to manually cut the parallax axis a bit to get rid of (presumably spurious) background stars. Make fe_h the aux axis in the “Form“ tab. If you look “from above“, you will see that the quality cuts have punched a hole into the cluster. If you look from the side, you can see that the cluster stars are (by and large) rather metal-poor compared to foreground stars:
Sorted by DB column index. [Sort alphabetically]
Name | Table Head | Description | Unit | UCD |
---|---|---|---|---|
source_id | Source Id | Gaia DR3 unique source identifier. You can match this against gaia.dr3lite on this TAP service. | N/A | meta.id;meta.main |
ra | RA | Gaia ICRS right ascension for this object. | deg | pos.eq.ra;meta.main |
dec | Dec | Gaia ICRS declination for this object. | deg | pos.eq.dec;meta.main |
teff | Teff | Estimated effective Temperature. Note that the raw HDF5 files released by Zhang et al. (2023) give Teff in a different unit (Kilokelvin). | K | phys.temperature.effective |
fe_h | [Fe/H] | Log of Fe/H in solar units | N/A | phys.abund.Fe |
logg | log(g) | Log of surface gravity in solar units | N/A | phys.gravity |
ext | Ext. | Estimated extinction parameter. To convert to the extension at a particular wavelength, multiply this by that wavelength's value in the extinction curve, available at https://zenodo.org/record/7811871/files/extinction_curve.txt?download=1 and in the footnote. [Note R] | mag | phys.absorption |
mod_parallax | Est. Par. | Parallax estimated from the model. | mas | pos.parallax |
err_teff | Err. Teff | Error in estimated effective temperature. Note that the raw HDF5 files released by Zhang et al. (2023) give the error in Teff in a different unit (Kilokelvin). | K | stat.error;phys.temperature.effective |
err_fe_h | Err. [Fe/H] | Error in fe_h | N/A | stat.error;phys.abund.Fe |
err_logg | Err. log(g) | Error in log_g | N/A | stat.error;phys.gravity |
err_ext | Err. Ext. | Error in ext | mag | stat.error;phys.absorption |
err_mod_parallax | Err. Par. | Error in the parallax estimated from the model. | mas | stat.error;pos.parallax |
chi2_opt | χ² | χ² of the best-fit solution. Divide by 61 to obtain χ² per degree of freedom. | N/A | stat.fit.chi2 |
ln_prior | ln(prior) | Natural log of the GMM prior on stellar type, at the location of the optimal solution. | N/A | stat.fit.goodness |
teff_confidence | Conf. T | A neural-network-based estimate of the confidence in the effective temperature estimate, on a scale of 0 (no confidence) to 1 (high confidence). | N/A | stat.fit.goodness |
feh_confidence | Conf. [Fe/H] | A neural-network-based estimate of the confidence in the [Fe/H] estimate, on a scale of 0 (no confidence) to 1 (high confidence). | N/A | stat.fit.goodness |
logg_confidence | Conf. logg | A neural-network-based estimate of the confidence in the log(g) estimate, on a scale of 0 (no confidence) to 1 (high confidence). | N/A | stat.fit.goodness |
quality_flags | Quality Flags | The three least significant bits represent whether the confidence in effective temperature, [Fe/H] and log(g) is less than 0.5, respectively. The 4th bit is set if chi2_opt/61 > 2. The 5th bit is set if ln_prior < -7.43. The 6th bit is set if our parallax estimate is more than 10 sigma from the GDR3 measurement (using reported parallax uncertainties from GDR3). The two most significant bits are always unset. We recommend a cut of quality_flags < 8 (the "basic reliability cut"), although a stricter cut of quality_flags == 0 ensures higher reliability at the cost of lower completeness. | N/A | meta.code.qual |
Columns that are parts of indices are marked like this.
The following services may use the data contained in this table:
VO nerds may sometimes need VOResource XML for this table.
This table is originally at https://zenodo.org/record/7811871/files/extinction_curve.txt?download=1.
wavelength | extinction_curve |
392.0 | 4.004029750823975 |
402.0 | 3.932934284210205 |
412.0 | 3.8616459369659424 |
422.0 | 3.790104627609253 |
432.0 | 3.66058611869812 |
442.0 | 3.6425302028656006 |
452.0 | 3.5208635330200195 |
462.0 | 3.42183256149292 |
472.0 | 3.3702077865600586 |
482.0 | 3.31054949760437 |
492.0 | 3.2349464893341064 |
502.0 | 3.103348970413208 |
512.0 | 3.028446674346924 |
522.0 | 2.913299798965454 |
532.0 | 2.8309452533721924 |
542.0 | 2.766111135482788 |
552.0 | 2.658158779144287 |
562.0 | 2.5784859657287598 |
572.0 | 2.5361363887786865 |
582.0 | 2.4805185794830322 |
592.0 | 2.412776470184326 |
602.0 | 2.356668472290039 |
612.0 | 2.313209056854248 |
622.0 | 2.272326707839966 |
632.0 | 2.2307708263397217 |
642.0 | 2.1915647983551025 |
652.0 | 2.156630516052246 |
662.0 | 2.1017379760742188 |
672.0 | 2.040684938430786 |
682.0 | 2.0002477169036865 |
692.0 | 1.9592469930648804 |
702.0 | 1.9099318981170654 |
712.0 | 1.8628478050231934 |
722.0 | 1.8250858783721924 |
732.0 | 1.7893791198730469 |
742.0 | 1.7572511434555054 |
752.0 | 1.7151219844818115 |
762.0 | 1.7081632614135742 |
772.0 | 1.6803325414657593 |
782.0 | 1.6145453453063965 |
792.0 | 1.566452145576477 |
802.0 | 1.5282924175262451 |
812.0 | 1.4971987009048462 |
822.0 | 1.4678758382797241 |
832.0 | 1.4417716264724731 |
842.0 | 1.4134937524795532 |
852.0 | 1.3825805187225342 |
862.0 | 1.3539363145828247 |
872.0 | 1.3050405979156494 |
882.0 | 1.2772356271743774 |
892.0 | 1.2389837503433228 |
902.0 | 1.2139592170715332 |
912.0 | 1.193802833557129 |
922.0 | 1.155206322669983 |
932.0 | 1.143110990524292 |
942.0 | 1.113704800605774 |
952.0 | 1.075573444366455 |
962.0 | 1.0743821859359741 |
972.0 | 1.0339452028274536 |
982.0 | 0.9810613989830017 |
992.0 | 1.0053104162216187 |
1235.0 | 0.6821472644805908 |
1662.0 | 0.4082775115966797 |
2159.0 | 0.2695426046848297 |
3352.6 | 0.13694290816783905 |
4602.8 | 0.09808244556188583 |