WFPC2 observations of the globular cluster M30

Brian Yanny, Puragra Guhathakurta, Donald P. Schneider, John N. Bahcall

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

We describe images of the center of the dense globular cluster M30 (NGC 7099) obtained with the Hubble Space Telescope Wide Field/Planetary Camera 2. Data taken in the F336W, F439W, and F555W filters (approximately U, B, and K) yield a color-magnitude diagram with photometric errors of 1 σ = 0.05 mag for stars with V < 17.5, and 1 σ ∼ 0.1 mag at V = 20, which is 1.5 mag fainter than the main-sequence turnoff. Simulations show that the star identifications are essentially complete for stars with V < 19.5, even in the densest regions of the cluster. The projected radial distribution of stars can be represented by a power law distribution: N(r) ∼ rα, with slope α = -0.4 ± 0.15, into radii less than 0″.4 (0.015 pc). The radial profile is also consistent with a flat core of any radius smaller than ∼ 1″.5 (0.05 pc), but inconsistent with any core radius larger than 2″.5 (0.09 pc). A total of 30 blue straggler candidates within 20″ of the cluster center have been identified from the three-color data. Their radial distribution is strongly centrally concentrated when compared to the horizontal branch, red giant branch, or main-sequence stars in the cluster. The abundance of blue stragglers (relative to red giants and subgiants) within r ≲ 20″ of the center of M30 is fBS = 0.19 ± 0.04, about twice as high as in other dense clusters.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume435
Issue number1 PART 2
StatePublished - Nov 1 1994

Fingerprint

globular clusters
stars
power law distribution
radial distribution
radii
diagram
filter
color-magnitude diagram
main sequence stars
Hubble Space Telescope
simulation
cameras
slopes
color
filters
distribution
profiles

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Yanny, B., Guhathakurta, P., Schneider, D. P., & Bahcall, J. N. (1994). WFPC2 observations of the globular cluster M30. Astrophysical Journal, 435(1 PART 2).
Yanny, Brian ; Guhathakurta, Puragra ; Schneider, Donald P. ; Bahcall, John N. / WFPC2 observations of the globular cluster M30. In: Astrophysical Journal. 1994 ; Vol. 435, No. 1 PART 2.
@article{cbd4b3dbc14449f49bb34ddfe74cd8dc,
title = "WFPC2 observations of the globular cluster M30",
abstract = "We describe images of the center of the dense globular cluster M30 (NGC 7099) obtained with the Hubble Space Telescope Wide Field/Planetary Camera 2. Data taken in the F336W, F439W, and F555W filters (approximately U, B, and K) yield a color-magnitude diagram with photometric errors of 1 σ = 0.05 mag for stars with V < 17.5, and 1 σ ∼ 0.1 mag at V = 20, which is 1.5 mag fainter than the main-sequence turnoff. Simulations show that the star identifications are essentially complete for stars with V < 19.5, even in the densest regions of the cluster. The projected radial distribution of stars can be represented by a power law distribution: N(r) ∼ rα, with slope α = -0.4 ± 0.15, into radii less than 0″.4 (0.015 pc). The radial profile is also consistent with a flat core of any radius smaller than ∼ 1″.5 (0.05 pc), but inconsistent with any core radius larger than 2″.5 (0.09 pc). A total of 30 blue straggler candidates within 20″ of the cluster center have been identified from the three-color data. Their radial distribution is strongly centrally concentrated when compared to the horizontal branch, red giant branch, or main-sequence stars in the cluster. The abundance of blue stragglers (relative to red giants and subgiants) within r ≲ 20″ of the center of M30 is fBS = 0.19 ± 0.04, about twice as high as in other dense clusters.",
author = "Brian Yanny and Puragra Guhathakurta and Schneider, {Donald P.} and Bahcall, {John N.}",
year = "1994",
month = "11",
day = "1",
language = "English (US)",
volume = "435",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1 PART 2",

}

Yanny, B, Guhathakurta, P, Schneider, DP & Bahcall, JN 1994, 'WFPC2 observations of the globular cluster M30', Astrophysical Journal, vol. 435, no. 1 PART 2.

WFPC2 observations of the globular cluster M30. / Yanny, Brian; Guhathakurta, Puragra; Schneider, Donald P.; Bahcall, John N.

In: Astrophysical Journal, Vol. 435, No. 1 PART 2, 01.11.1994.

Research output: Contribution to journalArticle

TY - JOUR

T1 - WFPC2 observations of the globular cluster M30

AU - Yanny, Brian

AU - Guhathakurta, Puragra

AU - Schneider, Donald P.

AU - Bahcall, John N.

PY - 1994/11/1

Y1 - 1994/11/1

N2 - We describe images of the center of the dense globular cluster M30 (NGC 7099) obtained with the Hubble Space Telescope Wide Field/Planetary Camera 2. Data taken in the F336W, F439W, and F555W filters (approximately U, B, and K) yield a color-magnitude diagram with photometric errors of 1 σ = 0.05 mag for stars with V < 17.5, and 1 σ ∼ 0.1 mag at V = 20, which is 1.5 mag fainter than the main-sequence turnoff. Simulations show that the star identifications are essentially complete for stars with V < 19.5, even in the densest regions of the cluster. The projected radial distribution of stars can be represented by a power law distribution: N(r) ∼ rα, with slope α = -0.4 ± 0.15, into radii less than 0″.4 (0.015 pc). The radial profile is also consistent with a flat core of any radius smaller than ∼ 1″.5 (0.05 pc), but inconsistent with any core radius larger than 2″.5 (0.09 pc). A total of 30 blue straggler candidates within 20″ of the cluster center have been identified from the three-color data. Their radial distribution is strongly centrally concentrated when compared to the horizontal branch, red giant branch, or main-sequence stars in the cluster. The abundance of blue stragglers (relative to red giants and subgiants) within r ≲ 20″ of the center of M30 is fBS = 0.19 ± 0.04, about twice as high as in other dense clusters.

AB - We describe images of the center of the dense globular cluster M30 (NGC 7099) obtained with the Hubble Space Telescope Wide Field/Planetary Camera 2. Data taken in the F336W, F439W, and F555W filters (approximately U, B, and K) yield a color-magnitude diagram with photometric errors of 1 σ = 0.05 mag for stars with V < 17.5, and 1 σ ∼ 0.1 mag at V = 20, which is 1.5 mag fainter than the main-sequence turnoff. Simulations show that the star identifications are essentially complete for stars with V < 19.5, even in the densest regions of the cluster. The projected radial distribution of stars can be represented by a power law distribution: N(r) ∼ rα, with slope α = -0.4 ± 0.15, into radii less than 0″.4 (0.015 pc). The radial profile is also consistent with a flat core of any radius smaller than ∼ 1″.5 (0.05 pc), but inconsistent with any core radius larger than 2″.5 (0.09 pc). A total of 30 blue straggler candidates within 20″ of the cluster center have been identified from the three-color data. Their radial distribution is strongly centrally concentrated when compared to the horizontal branch, red giant branch, or main-sequence stars in the cluster. The abundance of blue stragglers (relative to red giants and subgiants) within r ≲ 20″ of the center of M30 is fBS = 0.19 ± 0.04, about twice as high as in other dense clusters.

UR - http://www.scopus.com/inward/record.url?scp=12044258240&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=12044258240&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:12044258240

VL - 435

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1 PART 2

ER -

Yanny B, Guhathakurta P, Schneider DP, Bahcall JN. WFPC2 observations of the globular cluster M30. Astrophysical Journal. 1994 Nov 1;435(1 PART 2).