相关论文: The ultraviolet colour of globular clusters in M31…
We used observations obtained with the Ultraviolet Imaging Telescope on board the AstroSat satellite to measure the integrated far-ultraviolet (FUV) and optical (V) magnitudes of 30 Galactic globular clusters (GCs). We classified the…
We present high spatial resolution, far ultraviolet (FUV) F140LP observations of 12 massive globular clusters in M 31 obtained using the ACS/SBC on the Hubble Space Telescope (HST). These observations resolve the cluster profiles to scales…
We present ultraviolet photometry for globular clusters (GCs) in M31 from 15 square deg of imaging using the Galaxy Evolution Explorer (GALEX). We detect 200 and 94 GCs with certainty in the near-ultraviolet (NUV; 1750 - 2750 Angstroms) and…
We investigate the integrated far-ultraviolet (FUV) emission from globular clusters. We present new FUV photometry of M~87's clusters based on archival HST WFPC2 F170W observations. We use these data to test the reliability of published…
We present ultraviolet (UV) integrated colors of 44 Galactic globular clusters (GGCs) observed with the Galaxy Evolution Explorer (GALEX) in both FUV and NUV bands. We find for the first time that GCs associated with the Sagittarius dwarf…
We present ultraviolet (UV) integrated colors of 44 Galactic globular clusters (GGCs) observed with the Galaxy Evolution Explorer (GALEX) in both FUV and NUV bands. This data-base is the largest homogeneous catalog of UV colors ever…
Globular clusters represent stellar laboratories where observations can be used to validate models of stellar evolution. In this study, we put forth new ultraviolet (UV) photometric results of stars in the Galactic globular cluster NGC…
In recent years, increasing evidence for chemical complexity and multiple stellar populations in massive globular clusters (GCs) has emerged, including extreme horizontal branches (EHBs) and UV excess. Our goal is to improve our…
We investigate archival Hubble Space Telescope ACS/SBC F140LP observations of NGC~1399 to search for evidence of multiple stellar populations in extragalactic globular clusters. Enhanced FUV populations are thought to be indicators of…
The UV-initiative Hubble Space Telescope Treasury survey of Galactic globular clusters provides a new window into the phenomena that shape the morphological features of the horizontal branch (HB). Using this large and homogeneous catalog of…
Quillen et al. and O'Dea et al. carried out a Spitzer study of a sample of 62 brightest cluster galaxies (BCGs) from the ROSAT Brightest Cluster Sample chosen based on their elevated H-alpha flux. We present Hubble Space Telescope Advanced…
Blue horizontal branch and UV bright stars in several globular clusters are analysed spectroscopically and the results are compared with predictions of stellar evolutionary theory. We find that the distribution of temperatures and surface…
We study the origin of the UV-excess in star clusters by performing N-body simulations of six clusters with N=10k and N=100k (single stars & binary systems) and metallicities of Z=0.01, 0.001, and 0.0001, using PETAR. All models initially…
A recent study of hot (20,000 to 30,000 K) extreme horizontal branch (EHB) stars in globular clusters (GCs) has led to the discovery of their variability. It is suggested that this variability is driven by the projected rotation of magnetic…
We present ultraviolet (UV) photometry of M31 globular clusters (GCs) found in 23 Galaxy Evolution Explorer (GALEX) images covering the entirety of M31. We detect 485 and 273 GCs (and GC candidates) in the near-ultraviolet (NUV; 2267 A) and…
Far-ultraviolet (FUV) observations with the Hubble Space Telescope are an excellent way to find and study the hot, blue stellar populations in the cores of globular clusters. These populations include dynamically-formed blue stragglers and…
The ultraviolet (UV) light from a host star influences a planet's atmospheric photochemistry and will affect interpretations of exoplanetary spectra from future missions like the James Webb Space Telescope. These effects will be…
We present a study of the globular cluster (GC) systems of nearby elliptical and S0 galaxies at a variety of wavelengths from the X-ray to the infrared. Our analysis shows that roughly half of the low mass X-ray binaries (LMXBs), that are…
We investigate the relationship between Low Mass X-ray Binaries (LMXBs) and globular clusters (GCs) using UKIRT observations of M31 and existing Chandra, XMM-Newton, and ROSAT catalogues. By fitting King models to these data we have…
We have obtained HST/STIS far- and near-UV photometry of globular clusters in four fields in the gE galaxy M87. To a limit of m(FUV) = 25 we detect a total of 66 globular clusters (GCs) in common with the deep HST optical-band study of…