Globular Cluster Candidates in NGC 891

Abstract

We use deep images taken with the Advanced Camera for Surveys on board the Hubble Space Telescope of the disk galaxy NGC 891, to search for globular cluster candidates. This galaxy has long been considered to be a close analog in size and structure to the Milky Way and is nearly edge-on, facilitating studies of its halo population. These extraplanar ACS images, originally intended to study the halo field-star populations, reach deep enough to reveal even the faintest globular clusters that would be similar to those in the Milky Way. From the three pointings we have identified a total of 43 candidates after culling by object morphology, magnitude, and colour. We present (V,I) photometry for all of these, along with measurements of their effective radius and ellipticity. The 16 highest-rank candidates within the whole sample are found to fall in very much the same regions of parameter space occupied by the classic Milky Way globular clusters. Our provisional conclusion from this survey is that the total globular cluster population in NGC 891 as a whole may be almost as large as that of the Milky Way.

8 pages, 9 figures. In press for MNRAS

References in corpus (18)

• The Photometric Performance and Calibration of the HST Advanced Camera For Surveys
• Young massive star clusters in nearby galaxies. II.Software tools, data reductions and cluster sizes
• The cold gaseous halo of NGC 891
• The ACS Virgo Cluster Survey X. Half-light Radii of Globular Clusters in Early-Type Galaxies: Environmental Dependencies and a Standard Ruler for Distance Estimation
• Molecular Hydrogen in the FUSE Translucent Lines of Sight: The Full Sample
• A new population of extended, luminous star clusters in the halo of M31
• HST/ACS Wide-Field Photometry of the Sombrero Galaxy Globular Cluster System
• The Globular Cluster Systems of Five Nearby Spiral Galaxies: New Insights from Hubble Space Telescope Imaging
• ACS photometry of extended, luminous globular clusters in the outskirts of M31
• Globular clusters in the outer halo of M31: the survey
• Structural Parameters for Globular Clusters in NGC 5128
• Connection between the Age Distributions of Star Clusters and Field Stars: A First Application to the Small Magellanic Cloud
• Hubble Space Telescope observations of globular cluster systems along the Hubble sequence of spiral galaxies
• Global Properties of the Globular Cluster Systems of Four Spiral Galaxies
• M31's Undisturbed Thin Disk of Globular Clusters
• The Chemical Properties of Milky Way and M31 Globular Clusters: II. Stellar Population Model Predictions
• HST Imaging of Globular Clusters in the Edge--on Spiral Galaxies NGC 4565 and NGC 5907
• Imaging of star clusters in unperturbed spiral galaxies with the Advanced Camera for Surveys. I. The low luminosity galaxy NGC 45

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• A panoramic view of the Milky Way analogue NGC 891
• The ACS Fornax Cluster Survey VII. Half-Light Radii of Globular Clusters in Early-Type Galaxies
• A Catalog of Extended Clusters and Ultra-Compact Dwarf Galaxies - An Analysis of their Parameters in Early- and Late-Type Galaxies
• The stellar population content of the thick disk and halo of the Milky Way analogue NGC 891
• A Blue Tilt in the Globular Cluster System of the Milky Way-like Galaxy NGC 5170
• WIYN Imaging of the Globular Cluster Systems of the Spiral Galaxies NGC891 and NGC4013
• New Globular Cluster Candidates in the M81 group