Search Publications
A ultraluminous X-ray source associated with a cloud collision in M99
Soria, Roberto; Wong, Diane Sonya
The Sc galaxy M99 in the Virgo Cluster has been strongly affected by tidal interactions and recent close encounters, responsible for an asymmetric spiral pattern and a high star formation rate. Our XMM-Newton study shows that the inner disc is dominated by hot plasma at kT ~ 0.30 keV, with a total X-ray luminosity of ~1041ergs-1
The Spitzer View of Low-Metallicity Star Formation. I. Haro 3
Hunt, Leslie K.; Sauvage, Marc; Thuan, Trinh X. +1 more
We present Spitzer observations of the blue compact dwarf galaxy Haro 3, with an oxygen abundance of 12+log(O/H)=8.32. These data are part of a larger study of star formation and dust in low-metallicity environments. The IRS spectrum of Haro 3 shows strong narrow PAH emission, with high equivalent widths. Gaseous nebular fine-structure lines are a…
The first brown dwarf with a disk in Chamaeleon II
Alcalá, J. M.; Frasca, A.; Merín, B. +4 more
In this letter we characterize the candidates for young stars and brown dwarfs detected in a survey with ISOCAM in the Chamaeleon II dark cloud. Photometric data coming from a wide-field optical imaging survey, combined with IR measurements from the 2MASS catalogue and from the Spitzer satellite, allow us to study the nature of the candidates. Usi…
Traveling Convective Modes in the Sun's Subsurface Shear Layer
Kosovichev, A. G.; Green, C. A.
Observations reveal that supergranular convective cells on the Sun rotate faster than the plasma on the solar surface. Recent time-distance helioseismology results from the Solar and Heliospheric Observatory Michelson Doppler Imager suggest that supergranulation has properties of traveling waves. We consider the idea that these properties are rela…
Keck Spectroscopy of Globular Clusters in the Virgo Cluster Dwarf Elliptical Galaxy VCC 1386
Conselice, Christopher J.
We present the results of a Keck spectroscopic study of globular clusters associated with the Virgo Cluster dwarf elliptical galaxy (dE) VCC 1386. We analyze blue spectroscopic absorption lines from 3500 to 5500 Å for 13 globular cluster candidates and confirm that five are associated with VCC 1386. By comparing metal and Balmer line indices of th…
The properties of the circumnuclear regions in the Circinus galaxy
Bianchi, S.; Matt, G.; Nicastro, F. +2 more
We analysed the spectra from the XMM-Newton and the three longest Chandra observations of the Circinus Galaxy, the X-ray brightest, Compton-thick Seyfert 2 galaxy, to derive the physical and morphological parameters of the circumnuclear matter. We compare the line and continuum parameters with extensive calculations performed with the well-known p…
Imprints of Environment on Cluster and Field Late-Type Galaxies at z~1
Ford, H. C.; Demarco, R.; Menanteau, F. +6 more
We present a comparison of late-type galaxies (Sa and later) in intermediate-redshift clusters and in the field using images from the Advanced Camera for Surveys aboard the Hubble Space Telescope. Cluster and field galaxies are selected by matching photometric and spectroscopic catalogs of four cluster fields: Cl 0152-1357, Cl 1056-0337 (MS 1054),…
The Serendipitous XMM-Newton Cluster Athens Survey (SEXCLAS): sample selection and the cluster logN-logS
Georgakakis, A.; Georgantopoulos, I.; Plionis, M. +4 more
In this paper we serendipitously identify X-ray cluster candidates using XMM-Newton archival observations complemented by five-band optical photometric follow-up observations (r~ 23 mag) as part of the X-ray Identification (XID) programme. Our sample covers an area of ~2.1 deg2 (15 XMM-Newton fields) and comprises a total of 21 (19 sere…
Coordinated observation of field line resonance in the mid-tail
Russell, C. T.; Balogh, A.; Rème, H. +9 more
Standing Alfvén waves of 1.1 mHz (~15 min in period) were observed by the Cluster satellites in the mid-tail during 06:00-07:00 UT on 8 August 2003. Pulsations with the same frequency were also observed at several ground stations near Cluster's footpoint. The standing wave properties were determined from the electric and magnetic field measurement…
Bright X-Ray Transients in M31: 2004 July XMM-Newton Observations
Trudolyubov, Sergey; Priedhorsky, William; Cordova, France
We present the results of X-ray observations of four bright transients sources detected in the 2004 July XMM-Newton observations of the central bulge of M31. Two X-ray sources, XMMU J004315.5+412440 and XMMU J004144.7+411110, were discovered for the first time. Two other sources, CXOM31 J004309.9+412332 and CXOM31 J004241.8+411635, were previously…