Search Publications
The halo+cluster system of the Galactic globular cluster NGC 1851
Weiss, A.; Milone, A. P.; Marino, A. F. +17 more
NGC 1851 is surrounded by a stellar component that extends more than 10 times beyond the tidal radius. Although the nature of this stellar structure is not known, it has been suggested to be a sparse halo of stars or associated with a stellar stream. We analyse the nature of this intriguing stellar component surrounding NGC 1851 by investigating i…
A z = 2.5 protocluster associated with the radio galaxy MRC 2104-242: star formation and differing mass functions in dense environments
Kurk, J. D.; Rigby, E. E.; Hatch, N. A. +2 more
We present results from a narrow-band survey of the field around the high-redshift radio galaxy MRC 2104-242. We have selected Hα emitters in a 7 arcmin2 field and compared the measured number density with that of a field sample at similar redshift. We find that MRC 2104-242 lies in an overdensity of galaxies that is 8.0 ± 0.8 times the…
Observational constraints on variable equation of state parameters of dark matter and dark energy after Planck
Xu, Lixin; Kumar, Suresh
In this paper, we study a cosmological model in general relativity within the framework of spatially flat Friedmann-Robertson-Walker space-time filled with ordinary matter (baryonic), radiation, dark matter and dark energy, where the latter two components are described by Chevallier-Polarski-Linder equation of state parameters. We utilize the obse…
Evidence for a bimodal size distribution for the suspended aerosol particles on Mars
Maltagliati, L.; Montmessin, F.; Bertaux, J. -L. +4 more
First simultaneous analysis of the ultraviolet (UV) and infrared (IR) atmospheric extinctions from SPICAM/Mars Express solar occultations in the beginning of the Northern summer (Ls = 56-97°) is presented. The two SPICAM channels allow sounding of the martian atmosphere in the spectral range from 0.118 to 1.7 µm at the altitudes f…
Evidence of Titan's climate history from evaporite distribution
Sotin, Christophe; MacKenzie, Shannon M.; Barnes, Jason W. +8 more
Water-ice-poor, 5-µm-bright material on Saturn's moon Titan has previously been geomorphologically identified as evaporitic. Here we present a global distribution of the occurrences of the 5-µm-bright spectral unit, identified with Cassini's Visual Infrared Mapping Spectrometer (VIMS) and examined with RADAR when possible. We explore t…
Cold and Warm Atomic Gas around the Perseus Molecular Cloud. I. Basic Properties
Murray, Claire E.; Stanimirović, Snežana; Lee, Min-Young +2 more
Using the Arecibo Observatory, we have obtained neutral hydrogen (HI) absorption and emission spectral pairs in the direction of 26 background radio continuum sources in the vicinity of the Perseus molecular cloud. Strong absorption lines were detected in all cases, allowing us to estimate spin temperature (Ts ) and optical depth for 10…
A late-time view of the progenitors of five Type IIP supernovae
Mattila, Seppo; Maund, Justyn R.; Reilly, Emma
The acquisition of late-time imaging is an important step in the analysis of pre-explosion observations of the progenitors of supernovae. We present late-time Hubble Space Telescope Advanced Camera for Surveys Wide-Field Channel observations of the sites of five Type IIP SNe: 1999ev, 2003gd, 2004A, 2005cs and 2006my. Observations were conducted us…
A propeller scenario for the gamma-ray emission of low-mass X-ray binaries: the case of XSS J12270-4859
Torres, D. F.; Li, Jian; Papitto, A.
XSS J12270-4859 is the only low-mass X-ray binary (LMXB) with a proposed persistent gamma-ray counterpart in the Fermi-Large Area Telescope domain, 2FGL 1227.7-4853. Here, we present the results of the analysis of recent INTEGRAL observations, aimed at assessing the long-term variability of the hard X-ray emission, and thus the stability of the ac…
Abundance Enhancements in Impulsive Solar Energetic-Particle Events with Associated Coronal Mass Ejections
Reames, Donald V.; Kahler, Stephen W.; Cliver, Edward W.
We study the abundances of the elements He through Pb in Fe-rich impulsive solar energetic-particle (SEP) events with measurable abundances of ions with atomic number Z>2 observed on the Wind spacecraft, and their relationship with coronal mass ejections (CMEs) observed by the Large Angle and Spectrometric Coronagraph (LASCO) onboard the Solar …
The Supernova Progenitor Mass Distributions of M31 and M33: Further Evidence for an Upper Mass Limit
Dolphin, Andrew E.; Williams, Benjamin F.; Gilbert, Karoline M. +5 more
Using Hubble Space Telescope photometry to measure star formation histories, we age-date the stellar populations surrounding supernova remnants (SNRs) in M31 and M33. We then apply stellar evolution models to the ages to infer the corresponding masses for their supernova progenitor stars. We analyze 33 M33 SNR progenitors and 29 M31 SNR progenitor…