J/ApJ/793/135 Positions and distances of RR Lyrae stars (Sesar+, 2014)
Stacking the invisibles: a guided search for low-luminosity Milky Way
satellites.
Sesar B., Banholzer S.R., Cohen J.G., Martin N.F., Grillmair C.J.,
Levitan D., Laher R.R., Ofek E.O., Surace J.A., Kulkarni S.R., Prince T.A.,
Rix H.-W.
<Astrophys. J., 793, 135 (2014)>
=2014ApJ...793..135S 2014ApJ...793..135S (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Galaxies, nearby ; Stars, variable ; Stars, distances
Keywords: galaxies: dwarf - Galaxy: halo - Galaxy: structure -
stars: variables: RR Lyrae
Abstract:
Almost every known low-luminosity Milky Way dwarf spheroidal (dSph)
satellite galaxy contains at least one RR Lyrae star. Assuming that a
fraction of distant (60<dhelio<100 kpc) Galactic halo RR Lyrae
stars are members of yet to be discovered low-luminosity dSph
galaxies, we perform a guided search for these low-luminosity dSph
galaxies. In order to detect the presence of dSph galaxies, we combine
stars selected from more than 123 sightlines centered on RR Lyrae
stars identified by the Palomar Transient Factory. We find that this
method is sensitive enough to detect the presence of Segue 1-like
galaxies (MV=-1.5-0.8+0.6, rh=30 pc) even if only ∼20
sightlines were occupied by such dSph galaxies. Yet, when our method
is applied to the Sloan Digital Sky Survey Data Release 10 imaging
catalog, no signal is detected. An application of our method to
sightlines occupied by pairs of close (<200 pc) horizontal branch
stars, also did not yield a detection. Thus, we place upper limits on
the number of low-luminosity dSph galaxies with half-light radii from
30 pc to 120 pc, and in the probed volume of the halo. Stronger
constraints on the luminosity function may be obtained by applying our
method to sightlines centered on RR Lyrae stars selected from the
Pan-STARRS1 survey, and eventually, from the Large Synoptic Survey
Telescope. In Appendix A, we present spectroscopic observations of an
RRab star in the Bootes 3 dSph and a light curve of an RRab star
near the Bootes 2 dSph.
Description:
RRab stars used in this work were selected by an automated
classification algorithm that uses imaging data provided by the
Palomar Transient Factory survey (PTF). The PTF (Law et al.
2009PASP..121.1395L 2009PASP..121.1395L; Rau et al. 2009PASP..121.1334R 2009PASP..121.1334R) is a synoptic
survey designed to explore the transient sky. The project utilizes the
48-inch Samuel Oschin Schmidt Telescope on Mount Palomar. Each PTF
image covers 7.26 deg2 with a pixel scale of 1.01''. The typical PTF
cadence consists of two 60 s exposures separated by ∼1 hr and repeated
every one to five days. By 2013 June, PTF observed ∼11000 deg2 of sky
at least 25 times in the Mould-R filter (hereafter the R-band
filter), and about 2200 deg2 in the SDSS g' filter. PTF photometry
is calibrated to an accuracy of about 0.02 mag (Ofek et al.
2012PASP..124...62O 2012PASP..124...62O, 2012PASP..124..854O 2012PASP..124..854O) and light curves have
relative precision of better than 10 mmag at the bright end, and about
0.2 mag at the survey limiting magnitude of R=20.6 mag. The relative
photometry algorithm is described in Ofek et al. (2011, J/ApJ/740/65,
see their Appendix A).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 26 123 Positions and distances of RR Lyrae stars
--------------------------------------------------------------------------------
See also:
J/A+A/330/515 : RR Lyrae parallaxes + proper motions (Fernley+ 1998)
J/A+A/357/871 : RR Lyrae stars in the Sgr dwarf galaxy (Cseresnjes+, 2000)
J/AJ/132/1202 : RR Lyrae in Northern Sky Variability Survey (Kinemuchi+, 2006)
J/ApJ/740/65 : VLA search for 5GHz radio transients (Ofek+, 2011)
J/AJ/146/21 : LINEAR. II. Catalog of RR Lyrae stars (Sesar+, 2013)
J/ApJ/763/32 : Galactic halo RRab stars from CSS (Drake+, 2013)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
12- 20 F9.6 deg DEdeg Declination in decimal degrees (J2000)
22- 26 F5.2 kpc Dist Heliocentric distance (1)
--------------------------------------------------------------------------------
Note (1): Calculated assuming Mr=0.6 as the absolute magnitude of RR Lyrae
stars in the PTF R-band. The fractional uncertainty in distance is 6%.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 21-Apr-2017