Gaia early DR3 Mock Catalogue (gedr3mock)
This catalogue is a simulation of the
Gaia EDR3 stellar content using Galaxia (a tool to sample stars from a
Besancon-like Milky Way model), 3d dust extinction maps and the latest
PARSEC Isochrones. It is mimicking the Gaia DR2 data model
and an apparent magnitude limit of G=20,7. Extinctions and photometry
in different bands have also been included in a supplementary table as
well as uncertainty estimates using scaled GDR2 errors.
Additional magnitude limit per HEALpix maps are provided, based on the mode
in the magnitude distribution of Gaia DR2 data.
2019-12-01T13:08:00
20
astrostatistics-techniques
milky-way-galaxy
astronomical-simulations
Rybizki, J.; Demleitner, M.; Bailer-Jones, C.; Tio, P. D.;
Cantat-Gaudin, T.; Fouesneau, M.; Chen, Y.; Andrae, R.;
Girardi, L.; Sharma, S.
2020PASP..132g4501R
10.21938/dBrplG8I1KR7RyfkMXTyYA
Research
Simulation
Optical
Infrared
\internallink{/tableinfo/gedr3mock.main}
An internal stream to build the three-parameter sets for the
priam/FLAME-determined stuff.
Parsec-based photometry and extinction
for GeDR3 Mock
This table is intended to augment the Gaia photometry of GeDR3 Mock stars
with other bands and extinctions (Sloan, Johnson and 2MASS). The
grid was generated by binning all isochrones in logg, teff, and feh and
taking the median values of all isochrone models that fall within one
bin. We also report the median values of some astrophysical parameters so
that one can check how far the actual star abundances deviate from the
bin's median. For the extinction we report the extinction for the specific
isochrone bin in a specific photometric band for 6 different values of
monochromatic extinction, A_0, i.e. 1,2,3,5,10,20 mag.
Sometimes stars in GeDR3 Mock depart from the isochrone grid, because,
e.g., the feh value is outside of the grid or values have been
interpolated by Galaxia in the catalog generation from the Parsec
isochrones. Then the index_parsec is assigned to the nearest neighbour
in log_lum and log_teff.
bandName, bandLabel, descLabel, ucd
G, gaia_g, Gaia G, opt.V
BP_bright,gaia_bpbr, Gaia BP, opt.B
BP_faint, gaia_bpft, Gaia BP, opt.B
RP, gaia_rp, Gaia RP, opt.R
RVS, gaia_rvs, Gaia RVS, opt.R
U, ubv_u, Johnson U, opt.U
B, ubv_b, Johnson B, opt.B
V, ubv_v, Johnson V, opt.V
R, ubv_r, Johnson R, opt.R
I, ubv_i, Johnson I, opt.I
J, ubv_j, Johnson J, ir.J
H, ubv_h, Johnson H, ir.H
K, ubv_k, Johnson K, ir.K
L, ubv_l, Johnson L, ir.3-4um
M, ubv_m, Johnson M, ir.4-8um
u, sloan_u, SDSS u, opt.U
g, sloan_g, SDSS g, opt.V
r, sloan_r, SDSS r, opt.R
i, sloan_i, SDSS i, opt.I
z, sloan_z, SDSS z, opt.I
J, tmass_j, 2MASS J, ir.J
H, tmass_h, 2MASS H, ir.H
K', tmass_ks, 2MASS K', ir.K
bandName, bandLabel, descLabel, ucd
G, gaia_g, Gaia G, opt.V
BP_bright,gaia_bpbr, Gaia BP, opt.B
BP_faint, gaia_bpft, Gaia BP, opt.B
RP, gaia_rp, Gaia RP, opt.R
RVS, gaia_rvs, Gaia RVS, opt.R
u, sloan_u, SDSS u, opt.U
g, sloan_g, SDSS g, opt.V
r, sloan_r, SDSS r, opt.R
i, sloan_i, SDSS i, opt.I
z, sloan_z, SDSS z, opt.I
J, tmass_j, 2MASS J, ir.J
H, tmass_h, 2MASS H, ir.H
Ks, tmass_ks,2MASS Ks, ir.K
U, ubv_u, Johnson U, opt.U
B, ubv_b, Johnson B, opt.B
V, ubv_v, Johnson V, opt.V
R, ubv_r, Johnson R, opt.R
I, ubv_i, Johnson I, opt.I
JJ, ubv_j, Johnson J, ir.J
JH, ubv_h, Johnson H, ir.H
JK, ubv_k, Johnson K, ir.K
JL, ubv_j, Johnson L, ir.3-4um
JM, ubv_m, Johnson M, ir.4-8um
This contains the data actually generated.
Users probably want to use the gdr2mock.main table that
(fairly well) follows the Gaia DR2 data model.
name, type, unit, description, tablehead
teff, real, K, effective Temperature, Teff
feh, real, , log of metallicity in solar units ('dex'), [Fe/H]
a0, real, mag, monochramatic Extinction at lambda=547.7nm, A_0
lum, real, solLum, Stellar luminosity, Luminosity
l, double precision, deg, Galactic longitude, l
b, double precision, deg, Galactic latitude, b
smass, real, solMass, initial mass in solar masses, Mass_initial
age, real, Gyr, Age of the star, Age
logg, real, log(cm/(s**2)), Surface gravity of star, log(g)
phot_g_mean_mag, real, mag, apparent G mag including extinction, G
phot_bp_mean_mag, real, mag, apparent BP mag including extinction, BP
phot_rp_mean_mag, real, mag, apparent RP mag including extinction, RP
phot_rvs_mean_mag, real, mag, apparent RVS mag including extinction, RVS
popid, smallint, , Population ID according to the Besancon model. Including SMC/LMC = 10 and stellar clusters = 11, PopID
mact, real, solMass, actual (present) mass in solar masses, Mass_actual
phot_g_mean_mag_error, real, mag, error in G, error_G
a_g, real, mag, Extinction in G, A_G
a_bp, real, mag, Extinction in BP, A_BP
a_rp, real, mag, Extinction in RP, A_RP
a_rvs, real, mag, Extinction in RVS, A_RVS
parallax, real, mas, parallax in mas, parallax
radial_velocity, real, km/s, Radial velocity in km/s, V_rad
pm_ra, real, mas/yr, Proper motion in projection of right ascension, pm_alpha
pm_dec, real, mas/yr, Proper motion in declination, pm_delta
parallax_error, real, mas, parallax uncertainty in mas, error_parallax
radial_velocity_error, real, km/s, Radial velocity uncertainty in km/s, error_rvs
phot_g_n_obs, smallint, , Number of photometric observations (trained from DR2 scaled to DR3 time), Nobs
visibility_periods_used, smallint, , Number of observations effectively used for the astrometric solutions (trained from DR2 scaled to DR3), VPU
ebp_rp: EBP-RP
A synthetic Milky Way catalog mimicking
Gaia EDR3 in stellar content and data model.
`_ in many
situations.
Preferred form of spatial constraints
'''''''''''''''''''''''''''''''''''''
Please note that the standard (and fast) pattern for spatial
selections is cone-like; you can equivalently write::
WHERE distance(ra, dec, 66.73, 75.87)<2
or::
WHERE 1=CONTAINS(
POINT(ra, dec),
CIRCLE(66.73, 75.87, 2))
Both assume ADQL 2.1; in ADQL 2.0 (which still runs on the major Gaia
services in early 2019; this form also runs on ADQL 2.1), it's::
WHERE 1=CONTAINS(
POINT('', ra, dec),
CIRCLE('', 66.73, 75.87, 2))
*Do not* use “rectangular” selection ("ra between 1 and 2" or "ra<=2 and
ra>=1") – this will be slow and may introduce all kinds of weird effects
depending on the coordinate frame.
Chunking the catalog
''''''''''''''''''''
In some situations, you want to exhaustively partition the catalog.
To do that, use the ``source_id`` column, which has a healpix number in
the upper 29 bits. The following partition will yield chunks of no more
than 10 million objects::
limits = [
0, 161000525582565376, 190241590646669312,
205827580287254528, 238741701382897664, 260424586078715904,
281214461174349824, 376312424451538944, 419212653748027392,
434001497458475008, 459290814653136896, 473006912971997184,
506257553345216512, 518036827572011008, 530296897617788928,
561471797476720640, 759627535381168128, 944006495668797440,
1040369721951649792, 1255394304688390144, 1474976775439122432,
1741324705534574592, 1790290699963334656, 1808727482736574464,
1819886048289751040, 1822801609529229312, 1825109106478809088,
1827664749458882560, 1832812559820914688, 1838462125442334720,
1857229242740244480, 1864013813599174656, 1871967199678169088,
1929099026448252928, 1960210463870418944, 1971591440010051584,
1980320050506104832, 1997472672417579008, 2006800825988415488,
2016674749643489280, 2020634984368308224, 2023410014277861376,
2026188170923606016, 2029748561373036544, 2031976584247771136,
2034011161795493888, 2037941537907671040, 2045798957237403648,
2052181725315858432, 2059282715005419520, 2063545693384998912,
2073126425392578560, 2080238410198417408, 2092100903711539200,
2128972270234763264, 2163964193428996096, 2171955100342288384,
2179776957342810112, 2191148037877792768, 2202326978755821568,
2211928292246683648, 2231575809120796672, 2286857948095315968,
2639650169561284608, 2844586217717104640, 2928305335158439936,
2947826648713527296, 3014250448249946112, 3033455136815972352,
3047843655214694400, 3059447729135550464, 3101322766918352896,
3113168321080459264, 3128946862694858752, 3154598675129303040,
3242442335564333056, 3328470908460335104, 3351027045906776064,
3370789496105730048, 3398130467638083584, 3428571374765998080,
3445687163037941760, 3480352737437155328, 3733830299813937152,
4035615867629731840, 4036828663314907136, 4037599867642576896,
4038530810393919488, 4039095306535567360, 4039591701675769856,
4040246907526709248, 4040707156222148608, 4041261550600716288,
4041667820147179520, 4042098966144221184, 4042414835219038208,
4042752179130335232, 4043060523422449664, 4043363473235640320,
4043724868963794944, 4044015036954312704, 4044364131896131584,
4045435915215044608, 4045963199760039936, 4046800684023021568,
4048057700691476480, 4048868040761147392, 4049171128013291520,
4049506513419501568, 4049809463232692224, 4050069944409260032,
4050254799801679872, 4050418042918666240, 4050637910884483072,
4050833967551610880, 4051108433141694464, 4051576584576958464,
4052155511808720896, 4052449425010720768, 4052746739826819072,
4053179122774441984, 4054090617913868288, 4056095405568425984,
4056328948710113280, 4056576201387409408, 4058360193363214336,
4059134971103674368, 4059773409402290176, 4060841035192860672,
4061834065991434240, 4062363893157068800, 4062492261139611648,
4062658802791481344, 4062844929494220800, 4063012433218764800,
4063230067801587712, 4063918843116912640, 4064646857253453824,
4064985884791930880, 4065414763046240256, 4066361579996708864,
4067952504602624000, 4068619805081468928, 4069903038230298624,
4071285845900918784, 4073456488012578816, 4076157988082024448,
4077170191614607360, 4077951291546927104, 4079694739031457792,
4084865329900027904, 4088450768598728704, 4089692289025179648,
4090370584620302336, 4091069564777922560, 4092166636864274432,
4093254363101790208, 4094818177874132992, 4096497029050531840,
4097917357555449856, 4099795632653336576, 4101931537069506560,
4103357569290993664, 4104180175787261952, 4105068890420150272,
4106540724172881920, 4107362780913336320, 4108191091126173696,
4109639525897076736, 4110886028485591040, 4112922083502063616,
4116166123840339968, 4117045630063345664, 4118075357062496256,
4119249051365408768, 4120552178802753536, 4123114934248669184,
4125097937829101568, 4132304137037545472, 4138499163505557504,
4144234456674205696, 4145768687711813632, 4148283751840874496,
4151153339750416384, 4154588729471664128, 4156720235841323008,
4160109549153419264, 4164476053424701440, 4173161748607533056,
4183065084198649856, 4194740488936357888, 4201030485721219072,
4203246001651187712, 4204504083471532032, 4207748673565622272,
4214137351519076352, 4236123701424160768, 4249140888304877568,
4252016626607587328, 4252794771602407424, 4253810170590658560,
4254961050027294720, 4256649796808343552, 4259413384925020160,
4261775445139128320, 4263664062518263808, 4265313123801497600,
4267381442612297728, 4269142035606274048, 4274763254443540480,
4280098668977061888, 4285079628449579008, 4288820063928057856,
4292441202394923008, 4294774812745662464, 4297876672486572032,
4302944081060823040, 4307653873478139904, 4311003638731374592,
4313171051027628032, 4315005620538310656, 4317185780297498624,
4319582887444742144, 4322968180667449344, 4346606340634836992,
4372445757240770560, 4414351272111505408, 4471222102308945920,
4479473318600114176, 4490903429165613056, 4505091733368864768,
4508939336871313408, 4513839894556049408, 4517168391131234304,
4523225497609437184, 4537650746568474624, 4587791466092298240,
4651041147358019584, 4651929999429861376, 4654742378375020544,
4657309325709017088, 4658131141931302912, 4659220586155737088,
4685905458483953664, 4752009334496428032, 5048627575618797568,
5219424715445108736, 5233961496114888704, 5237655511586832384,
5241283796879278080, 5247578260430127104, 5253317539328425984,
5255512336336158720, 5259769920236814336, 5297659812484481024,
5305849353045278720, 5309762411849318400, 5313139321295863808,
5323313445985058816, 5331000028695625728, 5335160855573037056,
5337642556396142592, 5340266987572428800, 5343656403963740160,
5350462621457842176, 5354722576180445184, 5359458413279444992,
5372887470343979008, 5404963145103966208, 5410571788276989952,
5424220988185247744, 5442675225705578496, 5508257452170149888,
5521906755157622784, 5529933739796201472, 5540320791784062976,
5546108208675815424, 5583112135069663232, 5595949689238192128,
5601613136193912832, 5614335276001263616, 5621941697442217984,
5640128856716214272, 5671690544149954560, 5700966140751118336,
5716945240158371840, 5766837504414056448, 5792882426615169024,
5802883584381419520, 5818014616726274048, 5824544513204420608,
5827317722047840256, 5831197726783569920, 5833472822499868672,
5834633528821678080, 5835820554703077376, 5836584268607782912,
5844699317255798784, 5848652851831635968, 5850924511574097920,
5852524266632773632, 5854022419945095168, 5857492066325495808,
5858927272597127168, 5860855678553292800, 5862852907065409536,
5865046604561514496, 5869000963771072512, 5871370892365266944,
5874081463405641728, 5875585801470869504, 5876931225746145280,
5879421001107767296, 5881995988620541952, 5884080800105758720,
5887131841793622016, 5888770698234560512, 5890363031589748736,
5893058312546549760, 5895628043019354112, 5900250699140169728,
5904354901168750592, 5913874541561511936, 5919725420890030080,
5924441569858945024, 5926972130230009856, 5929102227850395648,
5930678309049335808, 5931684087310843904, 5932349738522247168,
5933174578401509376, 5934095969145585664, 5935796020280557568,
5937111070547116032, 5938525764054941696, 5940292851039469568,
5942406318546485248, 5944115818609508352, 5947882333129408512,
5950513670613106688, 5952165721193578496, 5953570931413614592,
5956003807048499200, 5957924550783008768, 5959238638976892928,
5960370448758734848, 5961583038285479936, 5963056933622513664,
5965315330505965568, 5968019063958405120, 5969643214431322112,
5971116078976204800, 5972674464909885440, 5976388340310605824,
5978043002231193600, 5979719860542767104, 5980600672435830784,
5983573786237075456, 5986047549960617984, 5988772071054770176,
5991739515499184128, 5995044510013325312, 6000602713090424832,
6009501438651138048, 6018305022096310272, 6022181968815325184,
6026558643569164288, 6028494643027509248, 6029656311421992960,
6032022529164443648, 6035830893845676032, 6046287902260854784,
6054119551786811392, 6057337650522619904, 6060242697682157568,
6064027697741299712, 6070987949942505472, 6076648098363342848,
6090704048854401024, 6105062502482051072, 6131616773444730880,
6189459537561387008, 6225770977788166144, 6260198885877088256,
6362808609516027904, 6442940742070435840, 6618300339755941888,
6652038613536079872, 6679890273859796992, 6706241753646628864,
6716109767426703360, 6722991267107569664, 6726135492405886976,
6728692372336541696, 6733950168221089792, 6736718979017998336,
6755124150831939584, 6762744900283793408, 6780826540801261568,
6866936202679812096, 8931576916874782720]
Please don't use it to dump the catalog yourself (see `Dump of the
catalog`_ for that); it might still come
in handy if you filter out a large part of the objects but still have
more than 20 million matches. Just regularly remove separation points.
The way to use it in python would be to say::
# make svc a TapService object with the right access URL, and then:
for low, high in zip(limits[:-1], limits[1:]):
partial = svc.run_sync("WITH sample AS ("
" SELECT * FROM \schema.main"
" WHERE source_id BETWEEN {} AND {})"
" ".format(low, high-1))
RVS magnitudes
''''''''''''''
These were calculated from the stellar spectra using the nominal RVS
passband. As it is uncertain whether this column will be provided in Gaia EDR3
it might still be useful for selection of RVS sample which can be done to the
real catalogs by equation 2 and 3 of :bibcode:`2018A&A...616A...1G`.
This is going to be severely off outside of 0.1
band, ucd
rp, R
bp, B
name, label, bands
bp_rp, BP-RP, em.opt.B;em.opt.R
bp_g, BP-G, em.opt.B;em.opt.V
g_rp, G-RP, em.opt.V;em.opt.R
For the contents of Gaia DR1 (and hence TGAS), which does not include
Solar System objects, the source ID consists of a 64-bit integer, least
significant bit = 1 and most significant bit = 64, comprising:
* a HEALPix index number (sky pixel) in bits 36 - 63; by definition the
smallest HEALPix index number is zero.
* a 2-bit Data Processing Centre code in bits 34 - 35; for example
MOD(source_id / 4294967296, 8) can be used to distinguish between
sources initialised via the Initial Gaia Source List by the Torino DPC
(code = 0) and sources otherwise detected and assigned by Gaia
observations (code > 0)
* a 25-bit plus 7 bit sequence number within the HEALPix pixel in bits 1
to 32 split into:
* a 25 bit running number in bits 8 x 32; the running numbers are
defined to be positive, i.e. never zero (except in the case of forced
empty windows)
* a 7-bit component number in bits 1 x 7 one spare bit in bit 33
This means that the HEALpix index level 12 of a given source is contained
in the most significant bits. HEALpix index of 12 and lower levels can
thus be retrieved as follows:
* HEALpix level 12 = source_id / 34359738368
* HEALpix level 11 = source_id / 137438953472
* HEALpix level 10 = source_id / 549755813888
* HEALpix level n = source_id / 2^35 * 4^(12 - level).
In the TGAS solution astrometric_delta_q (ΔQ)
indicates the discrepancy between the Hipparcos proper motion and the
TGAS proper motion. A large value of ΔQ could indicate non-linear motion
(e.g. in a binary).
For more details, see the paper referenced in the source metadata.
This is the excess noise ϵ\ :sub:`i` of the source. It measures the
disagreement, expressed as an angle, between the observations of a source
and the best-fitting standard astrometric model (using five astrometric
parameters). The assumed observational noise in each observation is
quadratically increased by ϵ\ :sub:`i`. in order to statistically match
the residuals in the astrometric solution. A value of 0 signifies that
the source is astrometrically well-behaved, i.e. that the residuals of
the fit statistically agree with the assumed observational noise. A
positive value signifies that the residuals are statistically larger than
expected.
The significance of ϵ\ :sub:`i` is given by astrometric_excess_noise_sig.
If this is larger than 2, then ϵ\ :sub:`i` is probably not significant,
and the source may be astrometrically well-behaved even if ϵ\ :sub:`i`
is large.
The excess noise may absorb all kinds of modelling errors that are not
accounted for by the observational noise (image centroiding error) or the
excess attitude noise. Such modelling errors include LSF and PSF
calibration errors, geometric instrument calibration errors, and part of
the high-frequency attitude noise. These modelling errors are
particularly important in the early data releases, but should decrease as
the astrometric modelling of the instrument and attitude improves over
the years.
Additionally, sources that deviate from the standard five-parameter
astrometric model (e.g. unresolved binaries, exoplanet systems, etc.) may
have positive excess noise. . Given the many other possible
contributions to the excess noise, the user must study the empirical
distributions of ϵ\ :sub:`i` and astrometric_excess_noise_sig.
to make sensible cutoffs before filtering out sources for their
particular application.
In Gaia DR1, the excess source noise has the same interpretation as
described above for both the primary (TGAS) and secondary data sets. It
measures the disagreement between the five-parameter model and the
observations, augmented by the different priors used. Thus, in TGAS the
excess noise may be increased if the proper motion seen during the 14
months of Gaia observations are not in agreement with the proper motion
inferred from the Tycho-2/Gaia comparison. In the secondary solution the
excess noise may be increased if the Gaia observations indicate a proper
motion or parallax several times larger than the prior uncertainty.
Number of AC or AL observations (= CCD transits) that were strongly
downweighted in the astrometric solution of the source, and therefore
contributed little to the determination of the astrometric parameters. An
observation is considered to be strongly downweighted if its
downweighting factor w < 0.2, which means that the absolute value of
the astrometric residual exceeds 4.83 times the total uncertainty of the
observation, calculated as the quadratic sum of the centroiding
uncertainty, excess source noise, and excess attitude noise.
Number of AC/AL observations (= CCD transits) that were not strongly
downweighted in the astrometric solution of the source. Strongly
downweighted observations (with downweighting factor w<0.2,
are instead counted in astrometric_n_bad_obs_ac/_al. The sum of
astrometric_n_good_obs_ac/_al and astrometric_n_bad_obs_ac/_al equals
astrometric_n_obs_ac/_al, the total number of AC/AL observations used in
the astrometric solution of the source.
Total number of AC/AL observations (= CCD transits) used in the
astrometric solution of the source, independent of their weight. Note
that some observations may be strongly downweighted (see
astrometric_n_bad_obs_ac/_al).
Nearly all sources having G<13 will have AC observations from
2d windows, while fainter than that limit only ∼ 1% of stars (the
so–called “calibration faint stars”) are assigned 2d windows
resulting in AC observations (this does not apply to AL).
Type of prior used in the astrometric solution:
0:
No prior used
1:
Galaxy Bayesian Prior for parallax and proper motion
2:
Galaxy Bayesian Prior for parallax and proper motion relaxed by factor
10
3:
Hipparcos prior for position
4:
Hipparcos prior for position and proper motion
5:
Tycho2 prior for position
6:
Quasar prior for proper motion
The Galaxy Bayesian Prior is defined in :bibcode:`2015A&A...583A..68M`,
where it is denoted σ\ :sub:`ϖ,F90` (for the parallax) and
σ\ :sub:`μ,F90` (for proper motion).
For Gaia DR1 the only types of priors used are 2 (for the secondary data
set), 3 (for the Hipparcos subset of the primary data set), or 5 (for the
non-Hipparcos subset of the primary data set). Type 6 was used for
internal calibration purposes and alignment of the reference frame, but
the corresponding astrometric results are in general not published.
Mean astrometric weight of the source in AC or AL direction.
The mean astrometric weight of the source is calculated as per Eq. (119)
in :bibcode:`2012A&A...538A..78L`\ .
All off-diagonal members entries of the covariance matrix
(ra_dec_corr, ra_pmra_corr, ra_pmdec_corr, dec_pmra_corr, dec_pmdec_corr,
pmra_pmdec_corr, ra_parallax_corr, dec_parallax_corr, parallax_pmra_corr,
parallax_pmdec_corr) are dimensionless values normalised to
between -1 and 1.
This may indicate observational, cross-matching or processing problems,
or stellar multiplicity, and probable astrometric or photometric problems
in all cases. In DR1, for close doubles with separations below some 2
arcsec, truncated windows have not been processed, neither in astrometry
and photometry. The transmitted window is centred on the brighter part of
the acquired window, so the brighter component has a better chance to be
selected, even when processing the fainter transit. If more than two
images are contained in a window, the result of the image parameter
determination is un-predictable in the sense that it might refer to
either (or neither) image, and no consistency is assured.
Flag indicating if variability was identified in the photometric G band:
* NULL: source not processed and/or exported to catalogue
* "CONSTANT": Source not identified as variable (not in this release)
* "VARIABLE": source identified and processed as variable;
see ivo://esavo/gaia/tap for more information on these objects.
Note that for this data release only a small subset of (variable) sources
was processed and/or exported, so for many (known) variable sources this
flag is set to NULL.
The scan_direction_strength and scan_direction_mean quantify
the distribution of AL scan directions across the source.
scan_direction_mean_kK (K=1..4) is 1/K times the argument of the
trigonometric moments m\ :sub:`k` = exp(ikθ), where
θ is the position angle of the scan and the mean value is taken over the
nObs[0] AL observations contributing to the astrometric parameters of the
source.
θ is defined in the usual astronomical sense:
θ = 0 when the FoV is moving towards local North, and θ = 90°
towards local East.
scan_direction_mean_kK is an angle between
-180°/K and 180°/K, giving the mean position angle of the scans
at order K. The different orders K
are statistics of the scan directions modulo 360°/K.
For example, at first order (K=1), θ = 10° and θ = 190°
count as different directions, but at second order (K = 2)
they are the same. Thus, scan_direction_mean_k1 is the mean
direction when the sense of direction is taken into account, while
scan_direction_mean_k2 is the mean direction without regard to the sense
of the direction.
For example, scan_direction_mean_k1 = 0 means that the scans
preferentially go towards North, while scan_direction_mean_k2 = 0 means
that they preferentially go in the North-South direction, and
scan_direction_mean_k4 = 0 that they preferentially go either in the
North-South or in the East-West direction.
The scan_direction_strength is a number between 0 and 1, where 0 means
that the scan directions are well spread out in different directions,
while 1 mean sthat they are concentrated in a single direction (given by
scan_angle_mean).
A temporary table used to insert
detectability information into generated_data. Not used
in operations.
This table gives empirical magnitude limits for
G and BP bands derived from Gaia DR2 with G < 20.7 mag for HEALPixels
of \level (scale roughly ~\resolution degrees). For each band
we have 4 different variants:
(1) no additional condition,
(2) parallax available,
(3) BP-RP available,
(4) parallax and BP-RP available.
For BP mag limits we also require that BP is available. The magnitude
limits are approximated by the mode of the magnitude distribution in a
specific HEALpix. Since this mode estimator is prone to Poisson noise
in low density areas we report the magnitude limits in two flavours:
(a) directly the mode estimator
(b) the same as the mode estimator,
except that in healpixel with a stellar density below 1e5 sources per
square degree the limit is arbitrarily set to 20.7 mag. These magnitude
limits were created using the `gdr2_completeness package`_ and users
are encouraged to create custom-made magnitude limits with specific
conditions, e.g. RVS sample with good parallaxes.
.. _gdr2_completeness package: https://github.com/jan-rybizki/gdr2_completeness
This table lists source_ids of gedr3mock objects that
are drawn at random using to the selection function found in
Gaia DR2 for stars with a full six-parameter solution as derived
in bibcode`TODO`. It is intended to be used to test selection
effects in observables on underlying stellar population parameter
distributions.
The completeness function was applied in spatial bins of HEALPix level
5, and bins of one each in GRVS magnitude and G-GRP color, yielding
7.2e6 sources.
\otherblurb
rvsdata/source_ids_gedr3mock_rvs_sample\srctag.csv
Gaia early DR3 Mock Bulk Download
res/downloadguard.html
from gavo import svcs
if inputTable.getParam("input")=="yes":
raise svcs.WebRedirect(
"http://vo.ari.uni-heidelberg.de/gedr3mock/dump.gz?")
else:
raise base.ValidationError("This must be 'yes' (without any"
" quotes)", "input")
data
/tap/sync
row = self.getFirstVOTableRow()
self.assertAlmostEqual(row["ra"], 283.319953674879)
self.assertAlmostEqual(row["phot_bp_mean_flux_error"], 1.0847477)
self.assertEqual(row["random_index"], 1372887323)
self.assertEqual(row["phot_g_n_obs"], 181)
self.assertAlmostEqual(row["a_g_val"], 0.191156)
self.assertAlmostEqual(row["A0_2_sloan_u"], 3.1199998855)
self.assertEqual(row["d11y"], 100)
/tap/sync
rows = self.getVOTableRows()
self.assertTrue(
{u'source_id': 4256653301501657248, u'd11y': 0}
in rows)
/gedr3mock/q/download
self.assertHTTPStatus(301)
self.assertHeader("location",
"http://vo.ari.uni-heidelberg.de/gedr3mock/dump.gz?")
/tap/sync
ids = [r["source_id"] for r in self.getVOTableRows()]
self.assertEqual(ids, [4256687661240025127])