Search Publications
Missions
Journals
Publication Years
Composition and structures of the subsurface in the vicinity of Valles Marineris as revealed by central uplifts of impact craters
Quantin, Cathy; Flahaut, Jessica; Clenet, Harold +2 more
Despite recent efforts from space exploration to sound the martian subsurface with RADAR, the structure of the martian subsurface is still unknown. Major geologic contacts or discontinuities inside the martian crust have not been revealed. Another way to analyze the subsurface is to study rocks that have been exhumed from depth by impact processes…
Modelling the very high energy flare of 3C 279 using one-zone leptonic model
Godambe, S.; Sahayanathan, S.
We model the simultaneous observations of the flat-spectrum radio quasar 3C 279 at radio, optical, X-ray and very high energy (VHE) gamma-ray energies during 2006 flare using a simple one-zone leptonic model. We consider synchrotron emission due to cooling of a non-thermal electron distribution in an equipartition magnetic field and inverse Compto…
The velocity dispersion and mass function of the outer halo globular cluster Palomar 4
Djorgovski, S. G.; Grebel, Eva K.; Côté, Patrick +5 more
We obtained precise line-of-sight radial velocities of 23 member stars of the remote halo globular cluster Palomar 4 (Pal 4) using the High Resolution Echelle Spectrograph at the Keck I telescope. We also measured the mass function of the cluster down to a limiting magnitude of V∼ 28 mag using archival Hubble Space Telescope/Wide Field Planetary C…
Can solar wind viscous drag account for coronal mass ejection deceleration?
Subramanian, Prasad; Lara, Alejandro; Borgazzi, Andrea
The forces acting on solar Coronal Mass Ejections (CMEs) in the interplanetary medium have been evaluated so far in terms of an empirical drag coefficient CD ∼ 1 that quantifies the role of the aerodynamic drag experienced by a typical CME due to its interaction with the ambient solar wind. We use a microphysical prescription for viscos…
Physical Properties of the Narrow-line Region of Low-mass Active Galaxies
Ho, Luis C.; Barth, Aaron J.; Greene, Jenny E. +1 more
We present spectroscopic observations of 27 active galactic nuclei (AGNs) with some of the lowest black hole (BH) masses known. We use the high spectral resolution and small aperture of our Keck data, taken with the Echellette Spectrograph and Imager, to isolate the narrow-line regions (NLRs) of these low-mass BHs. We investigate their emission-li…
Herschel observations of extended atomic gas in the core of the Perseus cluster
Baum, Stefi A.; O'Dea, Christopher P.; Donahue, Megan +11 more
We present Herschel observations of the core of the Perseus cluster of galaxies. Especially intriguing is the network of filaments that surround the brightest cluster galaxy, NGC 1275, previously imaged extensively in Hα and CO. In this work, we report detections of far-infrared (FIR) lines, in particular, [C II] 158, [O I] 63, [N II] 122, [O IB] …
The Cluster of Blue Stars Surrounding the M31 Nuclear Black Hole
Green, Richard F.; Kormendy, John; Lauer, Tod R. +2 more
We obtained U 330- and B-band images of the M31 nucleus using the High Resolution Camera of the Advanced Camera for Surveys on board the Hubble Space Telescope (HST). The spatial resolution in the U 330 band, 0farcs03 FWHM, or 0.1 pc at M31, is sufficient to resolve the outskirts of the compact cluster (P3) of UV-bright stars…
AKARI Observations of Brown Dwarfs. III. CO, CO2, and CH4 Fundamental Bands and Physical Parameters
Yamamura, I.; Sorahana, S.
We investigate variations in the strengths of three molecular bands, CH4 at 3.3 µm, CO at 4.6 µm, and CO2 at 4.2 µm, in 16 brown dwarf spectra obtained by AKARI. Spectral features are examined along the sequence of source classes from L1 to T8. We find that the CH4 3.3 µm band is present in …
The Panchromatic Hubble Andromeda Treasury. I. Bright UV Stars in the Bulge of M31
Bell, Eric F.; Skillman, Evan D.; Williams, Benjamin F. +20 more
As part of the Panchromatic Hubble Andromeda Treasury multi-cycle program, we observed a 12' × 6farcm5 area of the bulge of M31 with the WFC3/UVIS filters F275W and F336W. From these data we have assembled a sample of ~4000 UV-bright, old stars, vastly larger than previously available. We use updated Padova stellar evolutionary tracks to classify …
Study of LINER sources with broad Hα emission. Spectral energy distribution and multiwavelength correlations
Grosso, N.; Porquet, D.; Reeves, J. N. +2 more
Context. The geometry and physical properties of the accretion mode, and the radiative processes occurring in AGN-powered low ionization nuclear emission-line regions (LINERs) remain a riddle. Both a standard thin accretion disk and an inner-hot radiatively-inefficient accretion flow (RIAF) have been invoked. Models depending on only a jet have al…