Discovery of a faint old stellar system at 150 kpc

被引：77

作者：

Sakamoto, T. ^{[1
]}

Hasegawa, T.

机构：

[1] Natl Astron Observ, Okayama Astrophys Observ, Okayama 7190232, Japan

[2] Gunma Astron Observ, Gunma 3770702, Japan

来源：

ASTROPHYSICAL JOURNAL | 2006年 / 653卷 / 01期

基金：

美国国家科学基金会; 美国国家航空航天局;

关键词：

galaxies : dwarf; Galaxy : halo; globular clusters : general;

D O I：

10.1086/510332

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We report the detection of a faint old stellar system at (alpha, delta)=(194 degrees 29, 34 degrees 32) (SDSS J1257+3419), based on the spatial distribution of bright red giant branch stars in the Sloan Digital Sky Survey Data Release 4. SDSS J1257+3419 has a half-light radius of 38 +/- 12 pc and an absolute integrated V magnitude of M-v= -4.8=(1.4)(-1.0) mag at a heliocentric distance of 150 +/- 15 kpc. A comparison between SDSS J1257+3419 and known Galactic halo objects suggests that SDSS J1257+3419 is either (1) a faint and small dwarf galaxy or (2) a faint and widely extended globular cluster. In the former case, SDSS J1257+3419 could represent an entity of a postulated subhalo of the Milky Way. Further photometric and dynamical study of this stellar system is vital to distinguish these possibilities.

引用

页码：L29 / L32

页数：4

共 23 条

[1] The second data release of the Sloan Digital Sky Survey [J].

Abazajian, K ;

Adelman-McCarthy, JK ;

Agüeros, MA ;

Allam, SS ;

Kurt ;

Anderson, SJ ;

Anderson, SF ;

Annis, J ;

Bahcall, NA ;

Baldry, IK ;

Bastian, S ;

Berlind, A ;

Bernardi, M ;

Blanton, MR ;

Bochanski, JJ ;

Boroski, WN ;

Briggs, JW ;

Brinkmann, J ;

Brunner, RJ ;

Budavári, T ;

Carey, LN ;

Carliles, S ;

Castander, FJ ;

Connolly, AJ ;

Csabai, I ;

Doi, M ;

Dong, F ;

Eisenstein, DJ ;

Evans, ML ;

Fan, XH ;

Finkbeiner, DP ;

Friedman, SD ;

Frieman, JA ;

Fukugita, M ;

Gal, RR ;

Gillespie, B ;

Glazebrook, K ;

Gray, J ;

Grebel, EK ;

Gunn, JE ;

Gurbani, VK ;

Hall, PB ;

Hamabe, M ;

Harris, FH ;

Harris, HC ;

Harvanek, M ;

Heckman, TM ;

Hendry, JS ;

Hennessy, GS ;

Hindsley, RB .

ASTRONOMICAL JOURNAL, 2004, 128 (01) :502-512

[2] A faint new milky way satellite in Bootes [J].

Belokurov, V. ;

Zucker, D. B. ;

Evans, N. W. ;

Wilkinson, M. I. ;

Irwin, M. J. ;

Hodgkin, S. ;

Bramich, D. M. ;

Irwin, J. M. ;

Gilmore, G. ;

Willman, B. ;

Vidrih, S. ;

Newberg, H. J. ;

Wyse, R. F. G. ;

Fellhauer, M. ;

Hewett, P. C. ;

Cole, N. ;

Bell, E. F. ;

Beers, T. C. ;

Rockosi, C. M. ;

Yanny, B. ;

Grebel, E. K. ;

Schneider, D. P. ;

Lupton, R. ;

Barentine, J. C. ;

Brewington, H. ;

Brinkmann, J. ;

Harvanek, M. ;

Kleinman, S. J. ;

Krzesinski, J. ;

Long, D. ;

Nitta, A. ;

Smith, J. A. ;

Snedden, S. A. .

ASTROPHYSICAL JOURNAL, 2006, 647 (02) :L111-L114

[3] Reionization and the abundance of galactic satellites [J].

Bullock, JS ;

Kravtsov, AV ;

Weinberg, DH .

ASTROPHYSICAL JOURNAL, 2000, 539 (02) :517-521

[4] Theoretical isochrones in several photometric systems -: II.: The Sloan Digital Sky Survey ugriz system [J].

Girardi, L ;

Grebel, EK ;

Odenkirchen, M ;

Chiosi, C .

ASTRONOMY & ASTROPHYSICS, 2004, 422 (01) :205-215

[5] The impact of reionization on the stellar populations of nearby dwarf galaxies [J].

Grebel, EK ;

Gallagher, JS .

ASTROPHYSICAL JOURNAL, 2004, 610 (02) :L89-L92

[6] A catalog of parameters for globular clusters in the Milky Way [J].

Harris, WE .

ASTRONOMICAL JOURNAL, 1996, 112 (04) :1487-1488

[7] Candidate RR Lyrae stars found in Sloan Digital Sky Survey commissioning data [J].

Ivezic, Z ;

Goldston, J ;

Finlator, K ;

Knapp, GR ;

Yanny, B ;

McKay, TA ;

Amrose, S ;

Krisciunas, K ;

Willman, B ;

Anderson, S ;

Schaber, C ;

Erb, D ;

Logan, C ;

Stubbs, C ;

Chen, B ;

Neilsen, E ;

Uomoto, A ;

Pier, JR ;

Fan, XH ;

Gunn, JE ;

Lupton, RH ;

Rockosi, CM ;

Schlegel, D ;

Strauss, MA ;

Annis, J ;

Brinkmann, J ;

Csabai, I ;

Doi, M ;

Fukugita, M ;

Hennessy, GS ;

Hindsley, RB ;

Margon, B ;

Munn, JA ;

Newberg, HJ ;

Schneider, DP ;

Smith, JA ;

Szokoly, GP ;

Thakar, AR ;

Vogeley, MS ;

Waddell, P ;

Yasuda, N ;

York, DG .

ASTRONOMICAL JOURNAL, 2000, 120 (02) :963-977

[8] Where are the missing galactic satellites? [J].

Klypin, A ;

Kravtsov, AV ;

Valenzuela, O ;

Prada, F .

ASTROPHYSICAL JOURNAL, 1999, 522 (01) :82-92

[9] Photometric separation of stellar properties using SDSS filters [J].

Lenz, DD ;

Newberg, HJ ;

Rosner, R ;

Richards, GT ;

Stoughton, C .

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1998, 119 (02) :121-140

[10] Systematic errors in weak lensing: application to SDSS galaxy-galaxy weak lensing [J].

Mandelbaum, R ;

Hirata, CM ;

Seljak, U ;

Guzik, J ;

Padmanabhan, N ;

Blake, C ;

Blanton, MR ;

Lupton, R ;

Brinkmann, J .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2005, 361 (04) :1287-1322

← 1 2 3 →