PROBING THE OUTER GALACTIC HALO WITH RR LYRAE FROM THE CATALINA SURVEYS

By A. Drake, Márcio Catelán, S. George Djorgovski, G. Torrealba, M. Graham, V. Belokurov, Sergey E. Koposov, A. Mahabal, J. Prieto, C. Donalek and 3 more. 2012

161 citations recorded by the source corpus.

We present analysis of 12,227 type-ab RR Lyraes (RRLs) found among the 200 million public light curves in Catalina Surveys Data Release 1. These stars span the largest volume of the Milky Way ever surveyed with RRLs, covering ∼20,000 deg2 of the sky (0° < α < 360°, −22° < δ < 65°) to heliocentric distances of up to 60 kpc. Each of the RRLs is observed between 60 and 419 times over a six-year period. Using period finding and Fourier fitting techniques we determine periods and apparent magnitudes for each source. We find that the periods are generally accurate to σ = 0.002% in comparison to 2842 previously known RRLs and 100 RRLs observed in overlapping survey fields. We photometrically calibrate the light curves using 445 Landolt standard stars and show that the resulting magnitudes are accurate to ∼0.05 mag using Sloan Digital Sky Survey (SDSS) data for ∼1000 blue horizontal branch stars and 7788 RRLs. By combining Catalina photometry with SDSS spectroscopy, we analyze the radial velocity and metallicity distributions for >1500 of the RRLs. Using the accurate distances derived for the RRLs, we show the paths of the Sagittarius tidal streams crossing the sky at heliocentric distances from 20 to 60 kpc. By selecting samples of Galactic halo RRLs, we compare their velocity, metallicity, and distance with predictions from a recent detailed N-body model of the Sagittarius system. We find that there are some significant differences between the distances and structures predicted and our observations.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/9d8bc40df7bca35558b66738c7381b073b347128

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In Astronomy and Astrophysics

Citations in the corpus

A Population of Short-Period Variable Quasars from PTF as Supermassive Black Hole Binary Candidates (2016, methodology): “…et al. 2011; Djorgovski et al. 2012), an all-sky, time domain survey, in unfiltered visible light, calibrated to Jonhson V -band (e.g., see § 3 in Drake et al. 2013), with a limiting magnitude of 19-21.5.2 A particularly compelling member of this sample, PG1302102, is a bright (median V-band…”
25 Years of Self-Organized Criticality: Solar and Astrophysics (2014, methodology): “A model of energetic particles accelerated during multi-island magnetic reconnection that reproduces this energy spectrum was derived by Drake et al. (2013).”
A systematic search for close supermassive black hole binaries in the Catalina Real-time Transient Survey (2015, methodology): “The data are broadly calibrated to Johnson V (see Drake et al. 2013 for details) and the full CRTS data set4 contains time series for approximately 500 million sources.”
THE CATALINA SURVEYS PERIODIC VARIABLE STAR CATALOG (2014, methodology): “This result is in contrast to the peak of the RRab magnitude distribution from Drake et al. (2013a), which occurred at V = 17.”