Discovery of ∼9000 new RR Lyrae in the southern Catalina surveys. Issue 3 (24th November 2014)
- Record Type:
- Journal Article
- Title:
- Discovery of ∼9000 new RR Lyrae in the southern Catalina surveys. Issue 3 (24th November 2014)
- Main Title:
- Discovery of ∼9000 new RR Lyrae in the southern Catalina surveys
- Authors:
- Torrealba, G.
Catelan, M.
Drake, A. J.
Djorgovski, S. G.
McNaught, R. H.
Belokurov, V.
Koposov, S.
Graham, M. J.
Mahabal, A.
Larson, S.
Christensen, E. - Abstract:
- Abstract: We present the results of a deep, wide-area variability survey in the Southern hemisphere, the first of its kind. As part of the Catalina Sky Surveys, the Siding Spring Survey (SSS) has covered 14 800 deg 2 in the declination range of −75° ≤ δ ≤ −15°. To mine the enormous SSS data set efficiently, we have developed two algorithms: automatic period selection (APS) and automatic Fourier decomposition (AFD), which aim to sharpen the period estimation and produce robust light-curve models. Armed with the APS and AFD outputs, we classify 10 540 ab-type RR Lyrae (RRab) stars (∼90 per cent of which are new) across the southern sky. As well as the positional information we supply photometric metallicities, and unreddened distances. For the RRab stars in the halo, a study of the photometric metallicity distribution reveals a nearly Gaussian shape with a mean metallicity of [Fe/H] = −1.4 dex and a dispersion of 0.3 dex. A spatial study of the RRab metallicities shows no significant radial gradient in the first ∼7 kpc from the Galaxy centre. However, further out, a small negative gradient is clearly present. This is complemented by a very obvious correlation of the mean RR Lyrae metallicity with distance above the Galactic plane, z . We have also carried out an initial sub-structure search using the discovered RRab, and present the properties of the candidates with significance greater than 2σ. Most prominent among these is a southern extension of the Sagittarius dwarfAbstract: We present the results of a deep, wide-area variability survey in the Southern hemisphere, the first of its kind. As part of the Catalina Sky Surveys, the Siding Spring Survey (SSS) has covered 14 800 deg 2 in the declination range of −75° ≤ δ ≤ −15°. To mine the enormous SSS data set efficiently, we have developed two algorithms: automatic period selection (APS) and automatic Fourier decomposition (AFD), which aim to sharpen the period estimation and produce robust light-curve models. Armed with the APS and AFD outputs, we classify 10 540 ab-type RR Lyrae (RRab) stars (∼90 per cent of which are new) across the southern sky. As well as the positional information we supply photometric metallicities, and unreddened distances. For the RRab stars in the halo, a study of the photometric metallicity distribution reveals a nearly Gaussian shape with a mean metallicity of [Fe/H] = −1.4 dex and a dispersion of 0.3 dex. A spatial study of the RRab metallicities shows no significant radial gradient in the first ∼7 kpc from the Galaxy centre. However, further out, a small negative gradient is clearly present. This is complemented by a very obvious correlation of the mean RR Lyrae metallicity with distance above the Galactic plane, z . We have also carried out an initial sub-structure search using the discovered RRab, and present the properties of the candidates with significance greater than 2σ. Most prominent among these is a southern extension of the Sagittarius dwarf galaxy's stream system, reaching down to declinations ∼ -40 °. … (more)
- Is Part Of:
- Monthly notices of the Royal Astronomical Society. Volume 446:Issue 3(2015)
- Journal:
- Monthly notices of the Royal Astronomical Society
- Issue:
- Volume 446:Issue 3(2015)
- Issue Display:
- Volume 446, Issue 3 (2015)
- Year:
- 2015
- Volume:
- 446
- Issue:
- 3
- Issue Sort Value:
- 2015-0446-0003-0000
- Page Start:
- 2251
- Page End:
- 2266
- Publication Date:
- 2014-11-24
- Subjects:
- methods: data analysis -- methods: statistical -- stars: variables: RR Lyrae -- Galaxy: halo -- Galaxy: structure
Astronomy -- Periodicals
Periodicals
520.5 - Journal URLs:
- http://mnras.oxfordjournals.org/ ↗
http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2966 ↗
http://www.blackwell-synergy.com/issuelist.asp?journal=mnr ↗
http://www.blackwell-synergy.com/loi/mnr ↗
http://ukcatalogue.oup.com/ ↗ - DOI:
- 10.1093/mnras/stu2274 ↗
- Languages:
- English
- ISSNs:
- 0035-8711
- Deposit Type:
- Legaldeposit
- View Content:
- Available online (eLD content is only available in our Reading Rooms) ↗
- Physical Locations:
- British Library DSC - 5943.000000
British Library DSC - BLDSS-3PM
British Library HMNTS - ELD Digital store - Ingest File:
- 20852.xml