J/MNRAS/499/4040 RR Lyrae population in the Draco dwarf galaxy (Muraveva+, 2020)
A fresh look at the RR Lyrae population in the Draco dwarf spheroidal galaxy
with Gaia.
Muraveva T., Clementini G., Garofalo A., Cusano F.
<Mon. Not. R. Astron. Soc., 499, 4040-4053 (2020)>
=2020MNRAS.499.4040M 2020MNRAS.499.4040M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Galaxies, dwarf ; Parallaxes, trigonometric ;
Proper motions ; Optical
Keywords: stars: variables: RR Lyrae - galaxies: individual: Draco
Abstract:
We present a catalogue of 285 RR Lyrae stars (RRLs) in the Draco dwarf
spheroidal (dSph) galaxy, obtained by combining data from a number of
different surveys including the Data Release 2 (DR2) of the European
Space Agency cornerstone mission Gaia. We have determined individual
distances to the RRLs in our sample using for the first time a Gaia
G-band luminosity-metallicity relation (MG-[Fe/H]) and study the
structure of the Draco dSph as traced by its RRL population. We find
that the RRLs located in the western/south-western region of Draco
appear to be closer to us, which may be a clue of interaction between
Draco and the Milky Way. The average distance modulus of Draco
measured with the RRLs is µ=19.53±0.07mag, corresponding to a
distance of 80.5±2.6kpc, in good agreement with previous
determinations in the literature. Based on the pulsation properties of
the RRLs, we confirm the Oosterhoff-intermediate nature of Draco. We
present an additional sample of 41 candidate RRLs in Draco, which we
selected from the Gaia DR2 catalogue based on the uncertainty of their
G-band magnitudes. Additional epoch data that will become available in
the Gaia Data Release 3 will help to confirm whether these candidates
are bona fide Draco RRLs.
Description:
Our main goal was to compile the most complete as possible catalogue
of RRLs in the Draco dSph. Kinemuchi et al. (2008AJ....136.1921K 2008AJ....136.1921K, Cat.
J/AJ/136/1921) published mean V and I magnitudes, V amplitudes,
periods and photometric metallicities for 270 RRLs in this dSph, which
we have used as a starting point to build our own catalogue of RRLs in
Draco. As a first step, we searched for RRLs in the field of Draco in
the catalogues of currently available large variability surveys
(Catalina, ASAS, LINEAR, PTF, Pan-STARRS, GCVS). We selected from
these catalogues all RRLs located in a circular region of 2deg in
radius around the centre of Draco (RA=260.05162deg; Dec.=57.91536deg,
J2000). Such a rather large radius, significantly exceeding the
half-light radius of Draco (10arcmin, McConnachie 2012AJ....144....4M 2012AJ....144....4M,
Cat. J/AJ/144/4), was adopted in order to include RRLs located in the
outskirts of the galaxy and find those which might have been stripped
from Draco as a result of the interaction with the MW.
As a last step, we checked the lists of variable stars published in
the Gaia DR2 catalogue and available through the Gaia Archive website
(http://archives.esac.esa.int/gaia).
Compiling and cross-matching all the aforementioned catalogues, we
obtained a total sample of 379 variables of different types. Among
them 336 are classified as RRLs in at least one of the catalogues we
have analysed. In order to obtain the most complete census of the RRLs
in Draco, we proceeded with the full sample of 336 RRLs, even though
for some of them there is inconsistency of classification among the
various catalogues.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 116 285 Characteristics of our final sample of 285 RRLs
in Draco
table2.dat 54 3 New RRLs in Draco discovered by Gaia
table3.dat 72 7 RRLs whose membership to Draco is uncertain
table4.dat 52 51 Characteristics of 51 candidate RRLs discarded
from the sample of Draco RRLs
table5.dat 51 41 Candidate RRLs in Draco selected from the
Gaia DR2 catalogue based on the dispersion of
their G-band magnitudes (σG)
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/136/1921 : Variable stars of Draco dSph (Kinemuchi+, 2008)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
B/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)
J/AJ/153/204 : RR Lyrae stars from the PS1 3π survey (Sesar+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 29 F9.5 deg RAdeg Right ascension (ICRS) at Ep=2015.5
31- 38 F8.5 deg DEdeg Declination (ICRS) at Ep=2015.5
40- 48 A9 --- Ref References in literature where the source
was classified as RRL (1)
50- 53 A4 --- Type RRL type
55- 61 F7.5 d Period Pulstation period
63- 67 F5.3 mag Amp V-band amplitude
69- 73 F5.2 mas plx Gaia DR2 parallax
75- 78 F4.2 mas e_plx Error on plx
80- 84 F5.2 mas/yr pmRA Gaia DR2 proper motion in right ascension
86- 89 F4.2 mas/yr e_pmRA Error on pmRA
91- 95 F5.2 mas/yr pmDE Gaia DR2 proper motion in declination
97- 100 F4.2 mas/yr e_pmDE Error on pmDE
102- 107 F6.3 mag Gmag Gaia DR2 G-band magnitude
109 I1 --- r_Gmag Reference for Gmag (2)
111- 116 F6.3 mag mu Distance modulus
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Note (1): References as follows:
1 = Kinemuchi et al. (2008AJ....136.1921K 2008AJ....136.1921K, Cat. J/AJ/136/1921)
2 = the Gaia DR2 general variability detection classifiers (Eyer et al.
2017arXiv170203295E 2017arXiv170203295E, Rimoldini et al. 2019A&A...625A..97R 2019A&A...625A..97R)
3 = the Gaia SOS Cep&RRL pipeline (Clementini et al. 2019A&A...622A..60C 2019A&A...622A..60C,
Cat. J/A+A/622/A60)
4 = the GCVS (Samus et al. 2017ARep...61...80S 2017ARep...61...80S, Cat. B/gcvs)
5 = Pan-STARRS (Sesar et al. 2017AJ....153..204S 2017AJ....153..204S, Cat. J/AJ/153/204)
Note (2): Reference as follows:
1 = G mean magnitude from the DR2 gaia_source catalogue (Gaia Collaboration
2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345)
2 = G mean magnitude calculated in this study with the GRATIS software
3 = G mean magnitude taken from table: gaiadr2.vari_rrlyrae, which
summarizes results for RRLs obtained by the SOS Cep&RRL pipeline
(Clementini et al. 2019A&A...622A..60C 2019A&A...622A..60C, Cat. J/A+A/622/A60)
4 = G mean magnitude obtained transforming the V, I mean magnitudes of
Kinemuchi et al. (2008AJ....136.1921K 2008AJ....136.1921K, Cat. J/AJ/136/1921) to the Gaia
passbands with the transformation relations provided in Evans et al.
(2018A&A...616A...4E 2018A&A...616A...4E, Cat. I/345)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21 A1 --- Ref Reference for the data (1)
23- 26 A4 --- Type RRL type
28- 35 F8.6 d Period Pulstation period
37- 41 F5.3 mag Amp G-band amplitude
43- 48 F6.3 mag Gmag Gaia DR2 G-band magnitude
50- 54 F5.3 mag e_Gmag Error on Gmag
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Note (1): Reference as follows:
a = Parameters derived in this study using the GRATIS package
b = Parameters obtained by the Gaia SOS Cep&RRL pipeline
(Clementini et al. 2016A&A...595A.133C 2016A&A...595A.133C, Cat. I/337,
2019A&A...622A..60C 2019A&A...622A..60C, Cat. J/A+A/622/A60)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 29 F9.5 deg RAdeg Right ascension (ICRS) at Ep=2015.5
31- 38 F8.5 deg DEdeg Declination (ICRS) at Ep=2015.5
40- 47 A8 --- Ref Source of the data
49- 53 F5.2 mag mu Distance modulus
55- 58 F4.2 mag e_mu Error on mu
60- 64 F5.3 deg AngDist Angular distance from the centre of Draco
according to Kinemuchi et al.
(2008AJ....136.1921K 2008AJ....136.1921K, Cat. J/AJ/136/1921)
66- 72 F7.5 d Period Pulsation period
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 ? Gaia DR2 source identifier
21 A1 --- f_GaiaDR2 Flag on GaiaDR2 (1)
23- 31 F9.5 deg RAdeg Right ascension (ICRS) at Ep=2015.5
33- 40 F8.5 deg DEdeg Declination (ICRS) at Ep=2015.5
42- 52 A11 --- Ref References in literature where the source was
included (2)
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Note (1): Flag as follows:
b = No counterpart was found within 10arcsec in the Gaia DR2 catalogue
Note (2): References as follows:
1 = Kinemuchi et al. (2008AJ....136.1921K 2008AJ....136.1921K, Cat. J/AJ/136/1921)
2 = the Gaia DR2 general variability detection classifiers (Eyer et al.
2017arXiv170203295E 2017arXiv170203295E, Rimoldini et al. 2019A&A...625A..97R 2019A&A...625A..97R)
3 = the Gaia SOS Cep&RRL pipeline (Clementini et al. 2019A&A...622A..60C 2019A&A...622A..60C,
Cat. J/A+A/622/A60)
4 = the GCVS (Samus et al. 2017ARep...61...80S 2017ARep...61...80S, Cat. B/gcvs)
5 = Pan-STARRS (Sesar et al. 2017AJ....153..204S 2017AJ....153..204S, Cat. J/AJ/153/204)
6 = the Catalina Sky Survey
7 = the LINEAR survey
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 29 F9.5 deg RAdeg Right ascension (ICRS) at Ep=2015.5
31- 38 F8.5 deg DEdeg Declination (ICRS) at Ep=2015.5
40- 45 F6.3 mag Gmag Gaia DR2 G-band magnitude
47- 51 F5.3 mag e_Gmag Error on Gmag
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 07-Sep-2023