Search Publications
X-ray evidence for spectroscopic diversity of type Ia supernovae:. XMM observation of the elemental abundance pattern in M 87
Finoguenov, A.; Böhringer, H.; Arnaud, M. +2 more
We present the results of a detailed element abundance study of hot gas in M 87, observed by XMM-Newton. We choose two radial bins, 1'-3' and 8'-16' (8'-14' for EMOS; hereafter the central and the outer zones), where the temperature is almost constant, to carry out the detailed abundance measurements of O, Ne, Mg, Si, S, Ar, Ca, Fe and Ni using EP…
The Heavy-Element Enrichment of Lyα Clouds in the Virgo Supercluster
Gull, T. R.; Davé, R.; Heap, S. R. +11 more
Using high signal-to-noise ratio echelle spectra of 3C 273 obtained with the Space Telescope Imaging Spectrograph (resolution of 7 km s-1 FWHM), we constrain the metallicities of two Lyα clouds in the vicinity of the Virgo Cluster. We detect C II, Si II, and Si III absorption lines in the Lyα absorber at zabs=0.00530. Previou…
Revised Coordinates and Proper Motions of the Stars in the Luyten Half-Second Catalog
Bakos, Gáspár Á.; Sahu, Kailash C.; Németh, Péter
We present refined coordinates and proper-motion data for the high proper-motion (HPM) stars in the Luyten Half-Second (LHS) catalog. The positional uncertainty in the original Luyten catalog is typically greater than 10" and is often greater than 30". We have used the digital scans of the POSS I and POSS II plates to derive more accurate position…
A Hubble Space Telescope lensing survey of X-ray-luminous galaxy clusters - II. A search for gravitationally lensed EROs *
Kneib, J. -P.; Ivison, R. J.; Smith, Graham P. +7 more
We present the results of a survey for extremely red objects (EROs) undertaken in the fields of 10 massive galaxy cluster lenses at , combining sensitive, high-resolution Hubble Space Telescope imaging with deep, half-arcsecond K -band imaging from UKIRT. We detect 60 EROs with , of which 26 have in a total image-plane survey area of 49arcmin…
Interplanetary phenomena associated with very intense geomagnetic storms
Schwenn, R.; Tsurutani, B. T.; Lepping, R. P. +1 more
The dominant interplanetary phenomena that are frequently associated with intense magnetic storms are the interplanetary manifestations of fast coronal mass ejections (CMEs). Two such interplanetary structures, involving an intense and long duration Bs component of the IMF are: the sheath region behind a fast forward interplanetary shoc…
What Fraction of the Young Clusters in the Antennae Galaxies Are ``Missing''?
Whitmore, Bradley C.; Zhang, Qing
A reexamination of the correspondence between 6 cm radio continuum sources and young star clusters in the Antennae galaxies indicates that ~85% of the strong thermal sources have optical counterparts, once the optical image is shifted 1.2" to the southwest. A sample of 37 radio-optical matches are studied in detail, showing correlations between ra…
A Study of π Aquarii during a Quasi-normal Star Phase: Refined Fundamental Parameters and Evidence for Binarity
Bjorkman, Karen S.; Miroshnichenko, Anatoly S.; McDavid, David +1 more
We present the results of recent multicolor photometric and high-resolution spectroscopic observations of the bright Be star π Aqr. Observational data collected from the literature were used to study the star's variations over the last four decades. The star is identified with the IR sources F22227+0107 in the IRAS Faint Point Source Catalog and M…
PKS 1830-211: A Face-on Spiral Galaxy Lens
Rix, Hans-Walter; Winn, Joshua N.; Kochanek, Christopher S. +3 more
We present new Hubble Space Telescope images of the gravitational lens PKS 1830-211, which allow us to characterize the lens galaxy and update the determination of the Hubble constant (H0) from this system. The I-band image shows that the lens galaxy is a face-on spiral galaxy with clearly delineated spiral arms. The southwestern image …
The Dwarf Spheroidal Companions to M31: Variable Stars in Andromeda VI
Pritzl, Barton J.; Armandroff, Taft E.; Da Costa, Gary S. +1 more
We have surveyed Andromeda VI, a dwarf spheroidal galaxy companion to M31, for variable stars by using F450W and F555W observations obtained with the Hubble Space Telescope. A total of 118 variables were found, including 111 RR Lyrae stars, six anomalous Cepheids, and one variable that we were unable to classify. We find that the Andromeda VI anom…
Determination of the Distance to M33 Based on the Tip of the Red Giant Branch and the Red Clump
Sarajedini, Ata; Lee, Myung Gyoon; Geisler, Doug +2 more
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 10 regions of M33 based on HST/WFPC2 images. The regions used in this study are located at R=2.6‧-17.8‧ from the center of M33. The distance modulus to M33 obtained in this study, for an adopted foreground …