J/A+A/686/L2 Dormant 33 solar-masses black hole (Gaia Collaboration, 2024)
Discovery of a dormant 33 solar-masses black hole in pre-release Gaia
astrometry.
Gaia Collaboration, Panuzzo P., Mazeh T., Arenou F., Holl B., Caffau E.,
Jorissen A., Babusiaux C., Gavras P., Sahlmann J., Bastian U.,
Wyrzykowski L., Eyer L., Leclerc N., Bauchet N., Bombrun A., Mowlavi N.,
Seabroke G.M., Teyssier D., Balbinot E., Helmi A., Brown A.G.A.,
Vallenari A., Prusti T., de Bruijne J.H.J., Barbier A., Biermann M.,
Creevey O.L., Ducourant C., Evans D.W., Guerra R., Hutton A., Jordi C.,
Klioner S.A., Lammers U., Lindegren L., Luri X., Mignard F., Nicolas C.,
Randich S., Sartoretti P., Smiljanic R., Tanga P., Walton N.A., Aerts C.,
Bailer-Jones C.A.L., Cropper M., Drimmel R., Jansen F., Katz D.,
Lattanzi M.G., Soubiran C., Thevenin F., van Leeuwen F., Andrae R.,
Audard M., Bakker J., Blomme R., Castaneda J., De Angeli F., Fabricius C.,
Fouesneau M., Fremat Y., Galluccio L., Guerrier A., Heiter U., Masana E.,
Messineo R., Nienartowicz K., Pailler F., Riclet F., Roux W., Sordo R.,
Gracia-Abril G., Portell J., Altmann M., Benson K., Berthier J.,
Burgess P.W., Busonero D., Busso G., Cacciari C., Canovas H., Carrasco J.M.,
Carry B., Cellino A., Cheek N., Clementini G., Damerdji Y., Davidson M.,
de Teodoro P., Delchambre L., Dell'Oro A., Fraile Garcia E., Garabato D.,
Garcia-Lario P., Haigron R., Hambly N.C., Harrison D.L., Hatzidimitriou D.,
Hernandez J., Hestroffer D., Hodgkin S.T., Jamal S.,
Jevardat de Fombelle G., Jordan S., Krone-Martins A., Lanzafame A.C.,
Loeffler W., Lorca A., Marchal O., Marrese P.M., Moitinho A., Muinonen K.,
Nunez Campos M., Oreshina-Slezak I., Osborne P., Pancino E., Pauwels T.,
Recio-Blanco A., Riello M., Rimoldini L., Robin A.C., Roegiers T.,
Sarro L.M., Schultheis M., Smith M., Sozzetti A., Utrilla E.,
van Leeuwen M., Weingrill K., Abbas U., Abraham P., Abreu Aramburu A.,
Ahmed S., Altavilla G., Alvarez M.A., Anders F., Anderson R.I.,
Anglada Varela E., Antoja T., Baig S., Baines D., Baker S.G.,
Balaguer-Nunez L., Balog Z., Barache C., Barros M., Barstow M.A.,
Bartolome S., Bashi D., Bassilana J.-L., Baudeau N., Becciani U.,
Bedin L.R., Bellas-Velidis I., Bellazzini M., Beordo W., Bernet M.,
Bertolotto C., Bertone S., Bianchi L., Binnenfeld A., Blanco-Cuaresma S.,
Bland-Hawthorn J., Blazere A., Boch T., Bossini D., Bouquillon S.,
Bragaglia A., Braine J., Bratsolis E., Breedt E., Bressan A., Brouillet N.,
Brugaletta E., Bucciarelli B., Butkevich A.G., Buzzi R., Camut A.,
Cancelliere R., Cantat-Gaudin T., Capilla Guilarte D., Carballo R.,
Carlucci T., Carnerero M.I., Carretero J., Carton S., Casamiquela L.,
Casey A., Castellani M., Castro-Ginard A., Ceraj L., Cesare V., Charlot P.,
Chaudet C., Chemin L., Chiavassa A., Chornay N., Chosson D., Cooper W.J.,
Cornez T., Cowell S., Crosta M., Crowley C., Cruz Reyes M., Dafonte C.,
Dal Ponte M., David M., de Laverny P., De Luise F., De March R.,
de Torres A., del Peloso E.F., Delbo M., Delgado A., Delisle J.-B.,
Demouchy C., Denis E., Dharmawardena T.E., Di Giacomo F., Diener C.,
Distefano E., Dolding C., Dsilva K., Enke H., Fabre C., Fabrizio M.,
Faigler S., Fatovic M., Fedorets G., Fernandez-Hernandez J., Fernique P.,
Figueras F., Fouron C., Fragkoudi F., Gai M., Galinier M.,
Garcia-Serrano A., Garcia-Torres M., Garofalo A., Gerlach E., Geyer R.,
Giacobbe P., Gilmore G., Girona S., Giuffrida G., Gomboc A., Gomez A.,
Gonzalez-Santamaria I., Gosset E., Granvik M., Gregori Barrera V.,
Gutierrez-Sanchez R., Haywood M., Helmer A., Hidalgo S.L., Hilger T.,
Hobbs D., Hottier C., Huckle H.E., Jimenez-Arranz O., Juaristi Campillo J.,
Kaczmarek Z., Kervella P., Khanna S., Kontizas M., Kordopatis G., Korn A.J.,
Kospal A., Kostrzewa-Rutkowska Z., KruszyNska K., Kun M.,
Lambert S., Lanza A.F., Lebreton Y., Lebzelter T., Leccia S., Lecoutre G.,
Liao S., Liberato L., Licata E., Livanou E., Lobel A., Lopez-Miralles J.,
Loup C., Madarasz M., Mahy L., Mann R.G., Manteiga M., Marcellino C.P.,
Marchant J.M., Marconi M., Marin Pina D., Marinoni S., Marshall D.J.,
Martin Lozano J., Martin Polo L., Martin-Fleitas J.M., Marton G.,
Mascarenhas D., Masip A., Mastrobuono-Battisti A., McMillan P.J.,
Meichsner J., Merc J., Messina S., Millar N.R., Mints A., Mohamed D.,
Molina D., Molinaro R., Molnar L., Monguio M., Montegriffo P., Monti L.,
Mora A., Morbidelli R., Morris D., Mudimadugula R., Muraveva T., Musella I.,
Nagy Z., Nardetto N., Navarrete C., Oh S., Ordenovic C., Orenstein O.,
Pagani C., Pagano I., Palaversa L., Palicio P.A., Pallas-Quintela L.,
Pawlak M., Penttilae A., Pesciullesi P., Pinamonti M., Plachy E.,
Planquart L., Plum G., Poggio E., Pourbaix D., Price-Whelan A.M., Pulone L.,
Rabin V., Rainer M., Raiteri C.M., Ramos P., Ramos-Lerate M., Ratajczak M.,
Re Fiorentin P., Regibo S., Reyle C., Ripepi V., Riva A., Rix H.-W.,
Rixon G., Robert G., Robichon N., Robin C., Romero-Gomez M., Rowell N.,
Ruz Mieres D., Rybicki K.A., Sadowski G., Sagrista Selles A., Sanna N.,
Santovena R., Sarasso M., Sarmiento M.H., Sarrate Riera C., Sciacca E.,
Segransan D., Semczuk M., Shahaf S., Siebert A., Slezak E., Smart R.L.,
Snaith O.N., Solano E., Solitro F., Souami D., Souchay J., Spitoni E.,
Spoto F., Squillante L.A., Steele I.A., Steidelmueller H., Surdej J.,
Szabados L., Taris F., Taylor M.B., Teixeira R., Tepper-Garcia T.,
Thuillot W., Tolomei L., Tonello N., Torra F., Torralba Elipe G.,
Trabucchi M., Trentin E., Tsantaki M., Turon C., Ulla A., Unger N.,
Valtchanov I., Vanel O., Vecchiato A., Vicente D., Villar E., Weiler M.,
Zhao H., Zorec J., Zucker S., Zupic A., Zwitter T.
<Astron. Astrophys. 686, L2 (2024)>
=2024A&A...686L...2G 2024A&A...686L...2G (SIMBAD/NED BibCode)
ADC_Keywords: Positional data ; Binaries, orbits ; Binaries, spectroscopic ;
Radial velocities; Stars, halo ; Stars, population II
Keywords: astrometry - binaries: spectroscopic - stars: black holes -
stars: evolution - stars: massive - Stars: population II
Abstract:
We announce the serendipitous discovery of a nearby (590pc) binary
system composed of an old very metal-poor giant star orbiting a black
hole with an estimated mass of 33M☉, in 11.6yr. The system was
identified while validating the preliminary Gaia astrometric binary
solutions produced in preparation for Gaia DR4, and was confirmed by
Gaia RVS radial-velocity data.
Description:
We provide here the Gaia epoch astrometry and epoch radial velocity
data for the Gaia BH3 system.
The epoch astrometry table (tableb1.dat) presents the individual
astrometric Gaia measurements used to produce the binary-orbit
solution of Gaia BH3. As explained in the discovery paper, these
measurements are derived from preliminary runs of the Gaia
Consortium's data reduction pipelines in the development and
preparation for Gaia's Data Release 4 (DR4). They used provisional
instrument models and calibrations; thus they will not be identical
(but similar to) the corresponding data to be produced and published
for this star with DR4. Furthermore, the final epoch astrometry table
in DR4 will contain many additional details and quality diagnostics on
the individual measurements than the present table does. Each row of
the present table gives the minimum necessary data for one of the 622
individual astrometric measurements used in the BH3 discovery paper.
A Gaia epoch astrometry entry does not give a full 2-dimensional
position on the sky, but only a 1-dimensional measurement. Each of
these 1-dimensional measurements (denoted centroidposal) corresponds
to the longitude of the observed object in a 2-dimensional coordinate
system having its origin at the mean position of the star under
consideration, and having the axis of its longitude coordinate rotated
with respect to local ICRS North by a precisely known angle (denoted
scanposangle). This angle, as well as the times of the observations,
are determined by the rotational motion of the Gaia spacecraft, which
closely follows a pre-defined sky coverage pattern known as the Gaia
nominal scanning law (NSL).
The details of the definition of scanposangle and centroidposal,
and thus the precise meaning of the 1-dimensional measurements in the
table, are described in the public Gaia Consortium document LL-061 (L.
Lindegren & U. Bastian, 'Local plane coordinates for the detailed
analysis of complex Gaia sources',
https://dms.cosmos.esa.int/COSMOS/doc_fetch.php?id=504573). The
mathematical background and the usage of the data in the modelling of
astrometric source parameters is described in the publication by L.
Lindegren et al., 'The astrometric core solution for the Gaia
mission', Lindegren et al. (2012A&A...538A..78L 2012A&A...538A..78L), more specifically in
Section 5.1 of that publication.
The epoch RVS radial velocities (tableb2.dat), were produced with the
final pipeline, but not finalized with the post-processing; their
value or uncertainties may slightly differ from the final DR4 values.
Like for astrometry, the final epoch radial velocity table in DR4 will
contain additional details and quality diagnostics on the individual
measurements. Each epoch radial velocity record corresponds to a
transit of the source on the RVS CCDs. The provided observation time
of the radial velocity corresponds to the mean of the observation
times of the three CCDs used to collect spectra in the RVS during the
transit.
Objects:
-------------------------------------------------------------------
RA (2000) DE Designation(s)
-------------------------------------------------------------------
19 39 18.71 +14 55 54.0 Gaia BH3 = Gaia DR3 4318465066420528000
-------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tableb1.dat 78 622 Epoch astrometry data for Gaia BH3
tableb2.dat 46 17 Epoch radial velocities for Gaia BH3
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 I18 --- TransitID Unique identifier of the observation
(transit_id) (G1)
20 I1 --- CCDID CCD strip identifier (ccd_id) (G2)
22- 35 F14.6 d ObsTime Julian date (TCB) of the observation
(obstimetcb) (G3)
37- 44 F8.3 mas CentPosal The 1-dimensional measurement
(centroidposal) (G4)
46- 50 F5.3 mas e_CentPosal The formal standard error of it
(centroidposerror_al) (G5)
52- 62 F11.8 --- plxFactal Along-scan parallax factor
(parallaxfactoral) (G6)
64- 76 F13.8 deg ScanPA Scan direction at the star position
(scanposangle) (G7)
78 I1 --- outFlag [0/1] Indication whether the observation
is an outlier (outlier_flag) (G8)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 I18 ---- TransitID Unique identifier of the observation
(transit_id) (G1)
20- 33 F14.6 d ObsTime Julian date (TCB) of the observation
(obstimetcb) (G3)
35- 41 F7.2 km/s RV Radial velocity measurement
(radial_velocity) (G9)
43- 46 F4.2 km/s e_RV Formal error on the radial velocity
(radialvelocityerr)
--------------------------------------------------------------------------------
Global notes:
Note (G1): The transit_id is a unique identifier assigned to each detected
(and confirmed) celestial light source as its image transits the Gaia
focal plane. Each time a given source is detected while Gaia scans and
re-scans the sky, a new transit_id will be created to badge that apparition.
Hence, the time and the across-scan position plus the telescope
(field of view; either 1 or 2) in which the source was detected are used to
form a unique integer with which to label the transit. The detection of
transits is done using the SkyMapper CCD data, and the confirmation is done
using the AF1 CCD data. Both happens on board (for more explanations see the
on-line documentation of Gaia DR4
https://gea.esac.esa.int/archive/documentation/GDR3/ , Section 1.
The several features of a transit that are encoded in transit_id can be
easily retrieved using bit masks (&) and shifts (≫) as follows:
- On-Board Mission Time line (OBMT)
[ns] = 204800 * ((transit_id ≫ 17) & (0x000003FFFFFFFFFF))
- Field-of-view = 1 + (transit_id ≫ 15) & 0x03 [1 for 'preceding' and 2
for 'following' fields of view, respectively]
- CCD row = (transit_id ≫ 12) & 0x07 [dimensionless, range 1 to 7]
- Across-scan 'reference acquisition pixel' in strip AF1 =
(transitId) & 0x0FFF [pixels] (this is the across-scan centre of
the AF1 window and is odd if immediately below the mid-point of the
window, and even if immediately above) where the bit mask prefix '0x'
denotes hexadecimal.
For convenience, a decoder for transit_id is available on-line at
https://gaia.esac.esa.int/decoder/transitidDecoder.jsp
Note (G2): The ccd_id, in combination with the 'row' subitem of the
transit_id, gives the identity of the CCD detector chip which recorded the
present measurement. Precisely, it is the index of the CCD 'strip' on
Gaia's focal plane. The range of possible values is 1-9, corresponding to
CCD 'strips' AF1-AF9. For more explanations see the Gaia DR3 on-line
documentation at https://gea.esac.esa.int/archive/documentation/GDR3/,
specifically Section 1.1.3 and Figure 1.2.
Note (G3): For the astrometric table, the obstimetcb is the middle of the CCD
exposure time for this observation, given as Julian date, in days of 86400 SI
seconds of barycentric coordinate time (TCB). For the radial velocity table,
the obstimetcb refers to the mean of the observation times of the RVS CCDs
used to collect spectra in the RVS during the transit.
Note (G4): The centroidposal is the astrometric measurement. Precisely, it
is the along-scan local plane coordinate (w) of the image centroid position
in the sense of LL-061. It is given in the pseudo-angular unit of
milli-arcseconds (mas).
Note (G5): The centroidposerror al is the formal standard error of the
astrometric measurement centroidposal. It is given in the pseudo-angular
unit of milli-arcseconds.
Note (G6): The parallaxfactoral is the along-scan parallax factor in the
sense of LL-061. It is a dimension-less quantity in the range [-1,+1].
Note (G7): The scanposangle is the scan direction in the sense of LL-061,
i.e. the position angle of the long-scan local plane coordinate (w).
It is given in units of degrees in the range [-180,+180]. It is counted in
the conventional way, i.e. from local North, reaching the value of
90 degrees towards local East.
Note (G8): This flag indicates whether the given measurement was used in the
astrometric/spectroscopic modelling of Gaia BH3 (outlier_flag=0) or
considered as an outlier and ignored (outlier_flag=1).
Note (G9): Spectroscopic radial velocity in the Solar system barycentric
reference frame. It is given in units of km/s.
--------------------------------------------------------------------------------
Acknowledgements:
Pasquale Panuzzo, pasquale.panuzzo(at)obspm.fr
(End) U. Bastian [ARI, Heidelberg, Germany], P. Vannier [CDS] 03-Apr-2024