J/MNRAS/517/5368 RRds properties in Fornax dSph and Sculptor dSph (Braga+, 2022)
On the use of field RR Lyrae as galactic probes - VI. Mixed mode RR Lyrae
variables in Fornax and in nearby dwarf galaxies.
Braga V.F., Fiorentino G., Bono G., Stetson P.B., Martinez-Vazquez C.E.,
Kwak S., Tantalo M., Dall'Ora M., Di Criscienzo M., Fabrizio M.,
Marengo M., Marinoni S., Marrese P.M., Monelli M.
<Mon. Not. R. Astron. Soc. 517, 5368-5381 (2022)>
=2022MNRAS.517.5368B 2022MNRAS.517.5368B (SIMBAD/NED BibCode)
ADC_Keywords: Local group ; Galaxies, nearby ; Galaxies, dwarf ;
Stars, population II ; Stars, variable ; Optical ;
Photometry, UBVRI ; Positional data
Keywords: stars: variables: RR Lyrae - Local Group - Magellanic Clouds
Abstract:
We investigate the properties of the mixed-mode (RRd) RR Lyrae (RRL)
variables in the Fornax dwarf spheroidal (dSph) galaxy by using B- and
V-band time series collected over 24 yr. We compare the properties of
the RRds in Fornax with those in the Magellanic Clouds and in nearby
dSphs, with special focus on Sculptor. We found that the ratio of RRds
over the total number of RRLs decreases with metallicity. Typically,
dSphs have very few RRds with 0.49 ≲ P0 ≲ 0.53 d, but Fornax fills
this period gap in the Petersen diagram (ratio between first overtone
over fundamental period versus fundamental period). We also found that
the distribution in the Petersen diagram of Fornax RRds is similar to
Small Magellanic Cloud (SMC) RRds, thus suggesting that their old
stars have a similar metallicity distribution. We introduce the
Period-Amplitude RatioS diagram, a new pulsation diagnostics
independent of distance and reddening. We found that Large Magellanic
Cloud (LMC) RRds in this plane are distributed along a short- and a
long-period sequence that we identified as the metal-rich and the
metal- poor component. These two groups are also clearly separated in
the Petersen and Bailey (luminosity amplitude versus logarithmic
period) diagrams. This circumstantial evidence indicates that the two
groups have different evolutionary properties. All the pulsation
diagnostics adopted in this investigation suggest that old stellar
populations in Fornax and Sculptor dSphs underwent different chemical
enrichment histories. Fornax RRds are similar to SMC RRds, while
Sculptor RRds are more similar to the metal-rich component of the LMC
RRds.
Description:
We investigate RRds variable stars in Fornax dwarf galaxy (i.e see
Introduction, we use the same data set adopted in Fiorentino et al.
2017A&A...599A.125F 2017A&A...599A.125F, ∼1400 RRLs in Fornax) and further also extract
RRd candidates of Sculptor dwarf galaxy. We mainly focuse on optical
photometry (i.e extracted from section 2 : Based on more than 10000
optical images collected with ground-based telescopes. This work is
part of a larger project devoted in building up homogeneous photometry
for all the Milky Way satellites, including dSphs and GGCs. The
current photometric catalogue includes calibrated photometry for
737959 stars, with at least one measurement in two different bands are
in the field of Fornax.), by analysing BVRI LCs variabilities in order
to construct two samples presented in table1.dat and table2.dat. The
table1.dat regroups photometric data and the table2.dat presents
double periods and BVRI band amplitudes of selected 212 RRds Fornax
star variables plus 38 Sculptor RRd candidates for comparison (i.e
section 2 and section 3 for selection rules and search processes which
made us begin with 2266 periodic variables within the field of Fornax
of which 2068 were labelled as RRLs. Then as exposed in section 3.1 we
separate 212 multiperiodic double modes RRd from the RRLs sample).
Also see global diagnostics of RRd properties in section 4.
Objects:
----------------------------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------------------------
02 39 59.29 -34 26 56.9 Fornax Dwarf Galaxy = MCG-06-07-001
01 00 09.39 -33 42 32.0 Sculptor Dwarf Galaxy = Anon 0057-33
----------------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 86 212 Positions and mean magnitudes of the Fornax RRds
table2.dat 111 250 Pulsation properties of Fornax and Sculptor RRds
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See also:
J/MNRAS/502/818 : Periods and classifications of RR Lyrae in M15
(Hoffman+, 2021)
J/MNRAS/499/4040 : RR Lyrae population in the Draco dwarf galaxy
(Muraveva+, 2020)
J/MNRAS/494/1237 : Blazhko effect in Galactic RR Lyrae II (Skarka+, 2020)
J/MNRAS/480/1229 : Blazhko effect in the first overtone RR Lyrae (Netzel+,2018)
J/MNRAS/466/2602 : Blazhko effect in Galactic RR Lyrae (Prudil+, 2017)
J/MNRAS/462/4349 : Variable stars in Sculptor dSph (Martinez-Vazquez+, 2016)
J/MNRAS/452/4283 : 33 RR Lyrae observed in Pisces with K2-E2 (Molnar+, 2015)
J/A+A/674/A18 : Gaia DR3. The RR Lyrae sample (Clementini+, 2023)
J/A+A/625/A151 : Galactic Bulge Type II Cepheids NIR data (Braga+, 2019)
J/A+A/623/A116 : Galactic Cepheids and RR Lyrae multiplicity. I.
(Kervella+, 2019)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/A+A/592/A120 : Variable stars in NGC 6715 (Figuera Jaimes+, 2016)
J/A+A/580/A18 : Carina Project VIII. α-element abundances
(Fabrizio+, 2015)
J/A+A/578/A128 : VI light curves of NGC4590 variables (Kains+, 2015)
J/A+A/572/A88 : Measured equivalent widths for Fornax RGB stars
(Lemasle+, 2014)
J/A+A/544/A73 : BVI photometry of Fornax dSph galaxy (de Boer+, 2012)
J/A+A/421/937 : Metal abundances of LMC RR Lyrae (Gratton+, 2004)
J/A+A/375/909 : RR Lyrae stars in the Sgr dwarf (Cseresnjes 2001)
J/A+AS/121/327 : RR Lyr pulsational model (Bono+ 1997)
J/A+AS/112/407 : Variable Stars in the Sculptor dwarf galaxy (Kaluzny+, 1995)
J/ApJ/922/20 : CFHT optical & NIR obs. of RR Lyrae in M15 (Bhardwaj+, 2021)
J/ApJ/911/109 : RR Lyrae variable stars in DES Y6 (Stringer+, 2021)
J/ApJ/908/20 : On use of field RR Lyrae as galactic probes. II.
(Crestani+, 2021)
J/ApJ/814/71 : Carina project IX: UBVI data of Carina variables
(Coppola+, 2015)
J/ApJ/801/125 : Carbon in red giants in GCs and dSph galaxies (Kirby+, 2015)
J/ApJ/701/1323 : Variable stars in Fornax dSph. III. (Greco+, 2009)
J/ApJS/252/23 : E(V-I) reddening map of MCs from OGLE-IV RC stars
(Skowron+, 2021)
J/ApJS/247/68 : Probing the Gal. halo with RR Lyrae stars. I. (Liu+, 2020)
J/AJ/152/170 : RRLs in globulars. IV. UBVRI photometry in Omega Cen
(Braga+, 2016)
J/AJ/144/4 : Properties of dwarf galaxies in the Local Group
(McConnachie+, 2012)
J/AJ/136/1921 : Variable stars of Draco dSph (Kinemuchi+, 2008)
J/AJ/135/1459 : Period of M15 variable stars (Corwin+, 2008)
J/AJ/123/840 : VI photometry of variable stars in Fornax (Bersier+, 2002)
J/AcA/69/321 : OGLE RR Lyrae stars in Galactic bulge and disk
(Soszynski+, 2019)
J/AcA/64/177 : VI light curves of Galactic Bulge RR Lyrae (Soszynski+,2014)
J/AcA/61/285 : VI light curves of Galactic Bulge Cepheids (Soszynski+,2011)
I/356 : Gaia DR3 Part 2. Extra-galactic (Gaia Collaboration, 2022)
V/150 : Updated catalog of variable stars in globular clusters
(Clement+, 2017)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Name of the fornax rrd (name)
9- 17 F9.6 deg RAdeg Right ascension (J2000) (ra)
19- 28 F10.6 deg DEdeg Declination (J2000) (dec)
30- 35 F6.3 mag Vmag Mean V apparent magnitude in BVRI photometry
system (vmag)
37- 41 F5.3 mag e_Vmag Mean error of Vmag (errvmag)
43- 48 F6.3 mag Bmag Mean B apparent magnitude in BVRI photometry
system (bmag)
50- 54 F5.3 mag e_Bmag Mean error of Bmag (errbmag)
56- 62 F7.3 mag Rmag ?=-99 Mean R apparent magnitude in BVRI
photometry system (rmag)
64- 70 F7.3 mag e_Rmag ?=-99 Mean error of Rmag (errrmag)
72- 78 F7.3 mag Imag ?=-99 Mean I apparent magnitude in BVRI
photometry system (imag)
80- 86 F7.3 mag e_Imag ?=-99 Mean error of Imag (errimag)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- f_Name Indicates whether the RRd belonging either to
Fornax F for 212 cases or to Sculptor S for
38 cases (galaxy)
3- 9 A7 --- Name Name of the RRd (name)
11- 20 F10.8 d Pdom Dominant period (per_fo)
22- 33 F12.8 d Psec ?=-99 Secondary period (per_fu)
35 I1 --- f_Pdom Indicates the dominant period mode 0 for FU
fundamental 2 cases and 1 for FO first
overtone 248 cases (dominant_mode)
37- 40 F4.2 mag AmpV Amplitude in V-band (ampv)
42- 45 F4.2 mag e_AmpV Mean error of AmpV (err_ampv)
47- 50 F4.2 mag AmpB Amplitude in B-band (ampb)
52- 55 F4.2 mag e_AmpB Mean error of AmpB (err_ampb)
57- 62 F6.2 mag AmpR ?=-99 Amplitude in R-band (ampr)
64- 69 F6.2 mag e_AmpR ?=-99 Mean error of AmpR (err_ampr)
71- 76 F6.2 mag AmpI ?=-99 Amplitude in I-band (ampi)
78- 83 F6.2 mag e_AmpI ?=-99 Mean error of AmpI (err_ampi)
85- 90 F6.2 mag AmpVsec ?=-99 Amplitude in V-band of the secondary
period mode (ampv_sec)
92- 97 F6.2 mag e_AmpVsec ?=-99 Mean error of AmpVsec (errampvsec)
99-104 F6.2 mag AmpBsec ?=-99 Amplitude in B-band of the secondary
period mode (ampb_sec)
106-111 F6.2 mag e_AmpBsec ?=-99 Mean error of AmpBsec (errampbsec)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Fabrizio et al., Paper I 2019ApJ...882..169F 2019ApJ...882..169F
Crestani et al., Paper II 2021ApJ...908...20C 2021ApJ...908...20C, Cat. J/ApJ/908/20
Crestani et al., Paper III 2021ApJ...914...10C 2021ApJ...914...10C, Cat. J/ApJ/914/10
Fabrizio et al., Paper IV 2021ApJ...919..118F 2021ApJ...919..118F
Braga et al., Paper V 2021ApJ...919...85B 2021ApJ...919...85B, Cat. J/ApJ/919/85
Braga et al., Paper VII 2024A&A...689A.349B 2024A&A...689A.349B, Cat. J/A+A/689/A349
(End) Luc Trabelsi [CDS] 22-Oct-2025