The Metallicity of the Open Cluster Tombaugh 2 (2009)
Villanova, Sandro, Randich, Sofia, Geisler, Doug, Carraro, Giovanni, Costa, Edgardo
We investigate the nature of the chemical composition of the outer disc open cluster Tombaugh 2, that a recent study by Frinchaboy et al. (2008) suggested to possess an intrinsic metal abundance...
Woodley, Kristin A., Harris, William E., Puzia, Thomas H., Gomez, Matias, Harris, Gretchen L. H., Geisler, Doug
We present new integrated light spectroscopy of globular clusters (GCs) in NGC 5128 in order to measure radial velocities and derive ages, metallicities, and alpha-element abundance ratios. Using...
Lee, Myung Gyoon, Park, Hong Soo, Kim, Eunhyeuk, Hwang, Ho Seong, Kim, Sang Chul, Geisler, Doug
We present a photometric study of the globular clusters in the giant elliptical galaxy M60 in the Virgo cluster, based on deep, relatively wide field Washington CT_1 CCD images. The color-magnitude...
Washington Ccd Photometry Of The Old Open Cluster Tombaugh 2 (2007)
We have estimated a metal abundance of [Fe/H]= \Gamma0:48 \Sigma 0:14 dex, a reddening of E(B-V)= 0:30 mag, an age of 2:0 \Sigma 0:4 Gyr, and a distance of 7:9 \Sigma 0:8 kpc for Tombaugh 2 using the...
Interactions Of The Dwarf Irregular Galaxy Ugc 7636 With The Giant Elliptical Galaxy Ngc 4472 (2007)
Eunhyeuk Kim, Myung Gyoon Lee, Doug Geisler
this paper we present a study of the interactions of UGC 7636 with NGC 4472. Deep Washington CT 1 CCD images centered at NGC 4472 were obtained using the KPNO 4m telescope. In order to remove the...
Washington Ccd Photometry Of The Bulge Globular Cluster Ngc 6624 (2007)
Sung-Chul Yang, Myoung Gyoon Lee, Doug Geisler
INTRODUCTION About 150 globular clusters are known in the Galaxy. The metel rich population ([Fe/H]?-0.8dex)is concentrically distributed at the Galactic plane and the Galactic bulge. The metal poor...
Eva K. Grebel, Doug Geisler, Dante Minniti
Old and new tools for understanding the evolution of stars
Wide-Field Survey of Globular Clusters in M31. II. Kinematics of the Globular Cluster System (2007)
Lee, Myung Gyoon, Hwang, Ho Seong, Kim, Sang Chul, Park, Hong Soo, Geisler, Doug, Sarajedini, Ata, ...
We present a kinematic analysis of the globular cluster(GC) system in M31. Using the photometric and spectroscopic database of 504 GCs, we have investigated the kinematics of the M31 GC system. We...
Geisler, Doug, Wallerstein, George, Smith, Verne V., Casetti-Dinescu, Dana I.
We review Galactic halo formation theories and supporting evidence, in particular kinematics and detailed chemical abundances of stars in some relevant globular clusters as well as Local Group dwarf...
Wide-Field Survey of Globular Clusters in M31. I. A Catalog of New Clusters (2007)
Kim, Sang Chul, Lee, Myung Gyoon, Geisler, Doug, Sarajedini, Ata, Park, Hong Soo, Hwang, Ho Seong, ...
We present the result of a wide-field survey of globular clusters (GCs) in M31 covering a 3deg x 3deg field c. We have searched for GCs on CCD images taken with Washington CMT1 filters at the KPNO...
Hempel, Maren, Zepf, Steve, Kundu, Arunav, Geisler, Doug, Maccarone, Thomas J.
We present near-infrared photometry of the globular cluster systems of the early-type galaxies NGC 4472, NGC 4594, NGC 3585, and NGC 5813. We combine these near-infrared data, obtained with PANIC at...
The Stellar Populations of M33's Outer Regions III: Star Formation History (2006)
Barker, Michael K., Sarajedini, Ata, Geisler, Doug, Harding, Paul, Schommer, Robert
We present a detailed analysis of the star formation history (SFH) of three fields in M33 located ~ 4 - 6 visual scale lengths from its nucleus. These fields were imaged with the Advanced Camera for...
The Stellar Populations of M33's Outer Regions II: Deep ACS Imaging (2006)
Barker, Michael K., Sarajedini, Ata, Geisler, Doug, Harding, Paul, Schommer, Robert
Studying the stellar populations in the outskirts of spiral galaxies can provide important constraints on their structure, formation, and evolution. To that end, we present VI photometry obtained...
Newly Identified Star Clusters in M33. I. Integrated Photometry and Color-Magnitude Diagrams (2006)
Sarajedini, Ata, Barker, M. K., Geisler, Doug, Harding, Paul, Schommer, Robert
We present integrated photometry and color-magnitude diagrams (CMDs) for 24 star clusters in M33, of which 12 were previously uncataloged. These results are based on Advanced Camera for Surveys...
RR Lyrae Variables in M33. I. Evidence For a Field Halo Population (2006)
Sarajedini, Ata, Barker, M. K., Geisler, Doug, Harding, Paul, Schommer, Robert
We present observations of RR Lyrae variables in the Local Group late-type spiral galaxy M33. Using the Advanced Camera for Surveys on the Hubble Space Telescope, we have identified 64 ab-type RR...
Chou, Mei-Yin, Majewski, Steven R., Cunha, Katia, Smith, Verne V., Patterson, Richard J., Martinez-Delgado, David, ...
We present reliable measurements of the metallicity distribution function (MDF) at different points along the tidal stream of the Sagittarius (Sgr) dwarf spheroidal (dSph) galaxy, based on high...
Bizyaev, Dmitry, Smith, Verne V., Arenas, Jose, Geisler, Doug, Majewski, Steven R., Patterson, Richard J., ...
We present results from a campaign of multiple epoch echelle spectroscopy of relatively faint (V = 9.5-13.5 mag) red giants observed as potential astrometric grid stars for the Space Interferometry...
Low Mass X-ray Binaries in 6 Elliptical Galaxies: Connection to Globular Clusters (2005)
Kim, Eunhyeuk, Kim, Dong-Woo, Fabbiano, Giuseppina, Lee, Myung Gyoon, Park, Hong Soo, Geisler, Doug, ...
We present a systematic study of the low mass X-ray binary (LMXB) populations of 6 elliptical galaxies. We utilize Chandra archival data to identify 665 X-ray point sources and HST archival data...
The intermediate-age open clusters Ruprecht 4, Ruprecht 7 and Pismis 15 (2005)
Carraro, Giovanni, Geisler, Doug, Baume, Gustavo, Vazquez, Ruben, Moitinho, Andre
We report on $BVI$ CCD photometry to $V=22.0$ for 3 fields centered on the region of the Galactic star clusters Ruprecht~4, Ruprecht~7 and Pismis~15 and on 3 displaced control fields. Ruprecht~4 and...
Geisler, Doug, Smith, Verne V., Wallerstein, George, Gonzalez, Guillermo, Charbonnel, Corinne
We have used high-resolution, high signal-to-noise spectra obtained with the VLT and UVES to determine abundances of 17 elements in 4 red giants in the Sculptor dwarf spheroidal galaxy. Our [Fe/H]...
Forte, Juan C., Faifer, Favio, Geisler, Doug
Globular cluster systems (GCS) frequently show a bi-modal distribution of the cluster integrated colours. This work explores the arguments to support the idea that the same feature is shared by the...
The Globular Cluster System of NGC 1399. I. A Wide-field Photometric Study (2003)
Dirsch, Boris, Richtler, Tom, Geisler, Doug, Forte, Juan Carlos, Bassino, Lilia P., Gieren, Wolfgang P.
We present a photometric investigation of the globular cluster population of NGC 1399, the central galaxy in the Fornax cluster, in Washington C and Kron R filters within a field of 36'x36'. This is...
Doug Geisler, William E. Harris, Brian P. Schmidt, James E. Hesser, Mike Reid, ...
To investigate the global properties of the globular cluster system (GCS) around NGC 5128, the central giant elliptical galaxy in the nearby Centaurus group, we have obtained deep CCD imaging for an...
Dynamics of the globular cluster system associated with M87 (NGC 4486). II. Analysis (2001)
Cote, Patrick, McLaughlin, Dean, Hanes, David, Bridges, Terry, Geisler, Doug, Merritt, David, ...
Also archived in: arXiv:astro-ph/0106005 v1 31 May 2001
Lee, Myung Gyoon, Kim, Minsun, Sarajedini, Ata, Geisler, Doug, Gieren, Wolfgang
We have determined the distance to M33 using single epoch I-band observations of Cepheids based on HST/WFPC2 images of five fields in M33. Combining the HST I-band photometry and the periods...
Kim, Minsun, Kim, Eunhyeuk, Lee, Myung Gyoon, Sarajedini, Ata, Geisler, Doug
We have determined the distance to M33 using the tip of the red giant branch (TRGB) and the red clump (RC), from the VI photometry of stars in ten regions of M33 based on HST/WFPC2 images. The...
A Comparative Study of Globular Cluster Systems in UGC 9799 and NGC 1129 (2001)
Lee, Myung Gyoon, Kim, Eunhyeuk, Geisler, Doug, Bridges, Terry, Ashman, Keith
We present a preliminary analysis of HST-WFPC2 observations of globular cluster systems in the two brightest galaxies, UGC 9799 (cD) and NGC 1129 (non-cD), located in the center of rich clusters.
Washington Photometry of New Globular Clusters in M31 (2001)
Kim, Sang Chul, Lee, Myung Gyoon, Geisler, Doug, Seguel, Juan, Sarajedini, Ata, Harris, William E.
We present a progress report on Washington photometry of several hundred new globular cluster (GC) candidates in M31 which were recently found from our new CCD survey of GCs. Washington CMT1 filters...
Surface Photometry of Star Clusters in the Dwarf Elliptical Galaxies NGC 185 and NGC 205 (2001)
Kim, Sang Chul, Lee, Myung Gyoon, Geisler, Doug, Sarajedini, Ata, Armandroff, Taft E., Da Costa, Gary S.
We present the surface photometry of star clusters in the nearby dwarf elliptical galaxies NGC 185 and NGC 205, obtained from deep HST WFPC2 F555W (V) and F814W (I) images. We have obtained surface...
New CCD Survey of Globular Clusters in M31 (2001)
Lee, Myung Gyoon, Kim, Sang Chul, Geisler, Doug, Seguel, Juan, Sarajedini, Ata, Harris, William
We present a progress report of our wide field CCD survey of globular clusters in M31. We have covered 3 deg X 3 deg area centered on M31, using the KPNO 0.9m and Washington CMT1 filters. Our survey...
Hanes, David A., Cote, Patrick, Bridges, Terry J., McLaughlin, Dean E., Geisler, Doug, Harris, Gretchen L. H., ...
We present a comprehensive database of kinematic, photometric and positional information for 352 objects in the field of M87 (NGC 4486), the central giant elliptical galaxy in the Virgo cluster; the...
Dynamics of the Globular Cluster System Associated with M87 (NGC 4486). II. Analysis (2001)
Cote, Patrick, McLaughlin, Dean E., Hanes, David A., Bridges, Terry J., Geisler, Doug, Merritt, David, ...
We present a dynamical analysis of the globular cluster system associated with M87 (= NGC 4486), the cD galaxy near the dynamical center of the Virgo cluster. The analysis utilizes a new...
The Line-of-Sight Depth of Populous Clusters in the Small Magellanic Cloud (2001)
Crowl, Hugh H., Sarajedini, Ata, Piatti, Andres E., Geisler, Doug, Bica, Eduardo, Claria, Juan J., ...
We present an analysis of age, metal abundance, and positional data on populous clusters in the Small Magellanic Cloud (SMC) with the ultimate aim of determining the line-of-sight (LOS) depth of the...
The Star Cluster Systems of the Magellanic Clouds (2001)
Da Costa, G.S., Grebel, Eva K., Geisler, Doug, Minniti, Dante
The characteristics of the cluster systems of the Magellanic Clouds, as inferred from integrated properties, are compared with those from individual cluster studies and from the field population. The...
Globular Clusters as Probes of the Virgo gE NGC 4472 (2000)
Bridges, Terry, Ashman, Keith, Beasley, Mike, Sharples, Ray, Geisler, Doug, Hanes, Dave, ...
We present radial velocities for 144 globular clusters around the Virgo gE NGC 4472 (M49), and ages and metallicities from co-added spectra of 131 clusters. We confirm our earlier finding that the...
Dynamical Constraints on the Formation of NGC 4472 and Its Globular Clusters (2000)
Zepf, Stephen E., Beasley, Michael A., Bridges, Terry J., Hanes, David A., Sharples, Ray M., Ashman, Keith M., ...
We present new radial velocities for 87 globular clusters around the elliptical galaxy NGC 4472, and combine these with our previously published data to create a data set of velocities for 144...
Hubble Space Telescope Photometry of the Dwarf Spheroidal Galaxy ESO 410-G005 (2000)
Karachentsev, Igor D., Sharina, Margarita E., Grebel, Eva K., Dolphin, Andrew E., Geisler, Doug, Guhathakurta, Puragra, ...
We present HST WFPC2 imaging of the nearby low-surface-brightness dwarf spheroidal galaxy ESO 410-G005, which has been resolved into stars for the first time. The resulting color-magnitude diagram...
Kim, Eunhyeuk, Lee, Myung Gyoon, Geisler, Doug
We present deep wide field (16'.4 x 16'.4) Washington CT1 CCD surface photometry of the giant elliptical galaxy NGC 4472, the brightest member in the Virgo cluster. Our data cover a wider field than...
Sarajedini, Ata, Geisler, Doug, Harding, Paul, Schommer, Robert
We have constructed color-magnitude diagrams (CMDs) for ten globular clusters in the halo of the nearby spiral galaxy M33 based on Hubble Space Telescope Wide-Field Planetary Camera 2 observations in...
Bica, Eduardo, Geisler, Doug, Dottori, Horacio, Clariá, Juan J., Piatti, Andrés E., Santos Jr., João F. C.
We present Washington system C,T_1 CMDs of 13 star clusters and their surrounding fields which lie in the outer parts of the LMC disk. Ages are determined by means of the magnitude difference between...
Lee, Myung Gyoon, Kim, Eunhyeuk, Geisler, Doug
We present a comprehensive study of the luminosity function and spatial structure of the globular cluster system of NGC 4472, based on deep wide field Washington CT1 CCD images. The globular cluster...
A Search for Old Star Clusters in the Large Magellanic Cloud (1997)
Geisler, Doug, Bica, Eduardo, Dottori, Horacio, Clariá, Juan J., Piatti, Andrés E., Santos Jr., João F. C.
We report the first results of a color-magnitude diagram survey of 25 candidate old LMC clusters. For almost all of the sample, it was possible to reach the turnoff region, and in many clusters we...
Lee, Myung Gyoon, Kim, Eunhyeuk, Geisler, Doug
We present integrated Washington CT1 photometry of 18 bright blue objects discovered in the dwarf galaxy UGC 7636 which is located 5'.5 southeast of the giant elliptical galaxy NGC 4472, the...
Zepf, Stephen E., Ashman, Keith M., Geisler, Doug
We present a study of the colors of globular clusters associated with the elliptical galaxy NGC 3923. Our final sample consists of Washington system C and T_1 photometry for 143 globular cluster...