J/MNRAS/505/1135 Gaia/IPHAS catalogue of Ha-excess sources (Fratta+, 2021)
Population-based identification of Hα-excess sources in the Gaia DR2 and
IPHAS catalogues.
Fratta M., Scaringi S., Drew J.E., Monguio M., Knigge C., Maccarone T.J.,
Court J.M.C., Ilkiewicz K.A., Pala A.F., Gandhi P., Gaensicke B.
<Mon. Not. R. Astron. Soc. 505, 1135-1152 (2021)>
=2021MNRAS.505.1135F 2021MNRAS.505.1135F (SIMBAD/NED BibCode)
ADC_Keywords: Galactic plane ; Binaries, cataclysmic ; Photometry, H-alpha ;
Accretion
Keywords: techniques: photometric - catalogues - stars: emission-line, Be -
Hertzsprung-Russell and colour-magnitude - novae -
cataclysmic variables
Abstract:
We present a catalogue of point-like Hα-excess sources in the
Northern Galactic Plane. Our catalogue is created using a new
technique that leverages astrometric and photometric information from
Gaia to select Hα-bright outliers in the INT Photometric
Hα Survey of the Northern Galactic Plane (IPHAS), across the
colour-absolute magnitude diagram. To mitigate the selection biases
due to stellar population mixing and to extinction, the investigated
objects are first partitioned with respect to their positions in the
Gaia colour-absolute magnitude space, and in the Galactic coordinates
space, respectively. The selection is then performed on both partition
types independently. Two significance parameters are assigned to each
target, one for each partition type. These represent a quantitative
degree of confidence that the given source is a reliable
Hα-excess candidate, with reference to the other objects in the
corresponding partition. Our catalogue provides two flags for each
source, both indicating the significance level of the Hα-excess.
By analysing their intensity in the Hα narrow band, 28496
objects out of 7474835 are identified as Hα-excess candidates
with a significance higher than 3. The completeness fraction of the
Hα outliers selection is between 3% and 5%. The suggested 5sigma
conservative cut yields a purity fraction of 81.9%.
Description:
Catalogue of the Hα-excess candidates in the Gaia DR2 and IPHAS
DR2 surveys. The targets in the catalogue are located in the region of
the sky included between |b|<5° and 29<l<215°, within a
∼1.5kpc distance radius. For each of the 7474835 objects in the
catalogue, two significance parameters are provided; these quantify
our confidence that a given source is a robust H[alpha outlier. We
provide both a full and a light versions of the catalogue. The former
contains all the metrics produced during the selection process, while
the latter is narrowed down to the essential pieces of information.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
haexlit.dat 206 7474835 Light version of the Gaia/IPHAS catalogue of
the Ha-excess sources
HaExLit.fit 2880 311457 FITS version of haexlit.dat
haexfull.dat 568 7474835 Full version of the Gaia/IPHAS catalogue of
the Hα-excess sources
HaExFull.fit 2880 726729 FITS version of haexfull.dat
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
IV/36 : Gaia-IPHAS/KIS Value-Added Catalogues (Scaringi+, 2018)
Byte-by-byte Description of file: haexlit.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- SourceID Unique Gaia DR2 source identifier (Gaia DR2)
(SourceID)
21- 39 F19.15 deg RAdeg Gaia DR2 barycentric right ascension (ICRS)
at Epoch 2015.5 (RA)
41- 58 F18.15 deg DEdeg Gaia DR2 barycentric declination (ICRS)
at Epoch 2015.5 (Dec)
60- 78 F19.16 kpc Dist Parallax-inversion defined distance (Distance)
80- 88 F9.6 mag rmag r-band magnitude (IPHAS DR2) (r)
90-100 F11.9 mag e_rmag r-band magnitude error (IPHAS DR2) (e_r)
102-110 F9.6 mag imag i-band magnitude (IPHAS DR2) (i)
112-122 F11.9 mag e_imag i-band magnitude error (IPHAS DR2) (e_i)
124-132 F9.6 mag Hamag Ha-band magnitude (IPHAS DR2) (Ha)
134-144 F11.9 mag e_Hamag Ha-band magnitude error (IPHAS DR2) (e_Ha)
146-163 F18.15 mag BPMAG Integrated G_(BP) mean magnitude (Gaia DR2)
(G_(BP))
165-182 F18.15 mag RPMAG Integrated G_(RP) mean magnitude (Gaia DR2)
(G_(RP))
184-202 F19.16 mag GMAG G-band mean absolute magnitude (Gaia DR2)
(M_G)
204 I1 --- flagCAMD [0/2] CAMD flag (flagCAMD) (1)
206 I1 --- flagPOS [0/2] POS flag (flagPOS) (2)
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Note (1): CAMD flag as follows:
0 = if CAMDsigni <3
1 = if CAMDsigni between 3 and 5
2 = if CAMDsigni >5
Note (2): POS flag as follows:
0 = if POSsigni <3
1 = if POSsigni between 3 and 5
2 = if POSsigni >5
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Byte-by-byte Description of file: haexfull.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- SourceID Unique Gaia DR2 source identifier (Gaia DR2)
(SourceID)
21- 39 F19.15 deg RAdeg Gaia DR2 barycentric right ascension (ICRS)
at Epoch 2015.5 (RA)
41- 58 F18.16 deg e_RAdeg Standard error of right ascension (e_RA)
60- 77 F18.15 deg DEdeg Gaia DR2 barycentric declination (ICRS)
at Epoch 2015.5 (Dec)
79- 96 F18.16 deg e_DEdeg Standard error of declination (e_Dec)
98-116 F19.15 deg GLON Galactic longitude at Epoch 2015.5 (l_gal)
118-136 F19.16 deg GLAT Galactic latitude at Epoch 2015.5 (b_gal)
138-155 F18.15 mas plx Absolute stellar parallax (plx)
157-174 F18.16 mas e_plx Standard error of parallax (e_plx)
176-194 F19.16 kpc Dist Parallax-inversion defined distance (Distance)
196-214 F19.16 mag GMAG G-band mean absolute magnitude (Gaia DR2)
(M_G)
216-233 F18.15 mag BPMAG Integrated G_(BP) mean magnitude (Gaia DR2)
(G_(BP))
235-252 F18.15 mag RPMAG Integrated G_(RP) mean magnitude (Gaia DR2)
(G_(RP))
254-272 F19.16 mag BP-RP G_(BP) - G_(RP) colour (Gaia DR2) (BPmRP)
274-282 F9.6 mag rmag r-band magnitude (IPHAS DR2) (r)
284-294 F11.9 mag e_rmag r-band magnitude error (IPHAS DR2) (e_r)
296-304 F9.6 mag imag i-band magnitude (IPHAS DR2) (i)
306-316 F11.9 mag e_imag i-band magnitude error (IPHAS DR2) (e_i)
318-327 F10.7 mag r-i r-i colour (IPHAS DR2) (rmi)
329-339 F11.9 mag e_r-i r-i colour error (IPHAS DR2) (e_rmi)
341-349 F9.6 mag Hamag Ha-band magnitude (IPHAS DR2) (Ha)
351-361 F11.9 mag e_Hamag Ha-band magnitude error (IPHAS DR2) (e_Ha)
363-375 F13.10 mag r-Ha r-Ha colour (IPHAS DR2) (rmHa)
377-389 F13.11 mag e_r-Ha r-Ha colour error (IPHAS DR2) (e_rmHa)
391-394 I4 --- CAMDpart Colour-Absolute Magnitude partition identifier
(CAMD_partition)
396-414 F19.16 --- CAMDslope Slope of the best fit linear model for the
colour-absolute magnitude partition
(CAMD_slope)
416-435 F20.17 --- CAMDinter Intercept of the best fit linear model for the
colour-absolute magnitude partition
(CAMD_intercept)
437-452 F16.14 --- CAMDstd Standard Deviation of the underlying
population in the r-Ha_(detrended) direction,
for the colour-absolute magnitude partition
(CAMD_std)
454-473 F20.16 --- CAMDsigni r-Ha_(detrended) values in units of standard
deviation, for the colour-absolute magnitude
partition (CAMD_significance)
475-478 I4 --- POSpart Positional partition identifier
(POS_partition)
480-497 F18.16 --- POSslope Slope of the best fit linear model for the
positional partition (POS_slope)
499-518 F20.17 --- POSinter Intercept of the best fit linear model for the
positional partition (POS_intercept)
520-535 F16.14 --- POSstd Standard Deviation of the underlying
population in the r-Ha_(detrended) direction,
for the positional partition (POS_std)
537-556 F20.16 --- POSsigni r-Ha_(detrended) values in units of standard
deviation, for the positional partition
(POS_significance)
558-562 F5.3 --- fc [0/1] Completeness fraction (Scaringi et al.,
2018MNRAS.481.3357S 2018MNRAS.481.3357S, Cat. IV/36) (f_c)
564-568 F5.3 --- fFP [0/1] False-Positive rate (Scaringi et al.,
2018MNRAS.481.3357S 2018MNRAS.481.3357S, Cat. IV/36) (f_FP)
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Acknowledgements:
Matteo Fratta, matteo.fratta(at)durham.ac.uk
(End) Patricia Vannier [CDS] 14-May-2021