Search Publications
Chandrayaan-1 mission to the Moon
Goswami, Jitendra Nath; Annadurai, Mylswamy
Chandrayaan-1 is the first Indian planetary exploration mission that will perform remote sensing observation of the Moon to further our understanding about its origin and evolution. Hyper-spectral studies in the 0.4- 3µm region using three different imaging spectrometers, coupled with a low energy X-ray spectrometer, a sub-keV atom analyzer,…
Suzaku Observations of Hercules X-1: Measurements of the Two Cyclotron Harmonics
Dotani, Tadayasu; Enoto, Teruaki; Kokubun, Motohide +10 more
The accretion-powered pulsar Her X-1 was observed with Suzaku twice in its main-on state, on 2005 October 5--6 and 2006 March 29--30, for a net exposure of 30.5ks and 34.4ks, respectively. In the 2005 and 2006 observations, the source was detected at an average 10--30keV intensity of 290mCrab and 230mCrab, respectively. The intrinsic pulse period …
Measurements of methane absorption by the descent imager/spectral radiometer (DISR) during its descent through Titan's atmosphere
Tomasko, M. G.; Bézard, B.; Doose, L. +2 more
New low-temperature methane absorption coefficients pertinent to the Titan environment are presented as derived from the Huygens DISR spectral measurements combined with the in-situ measurements of the methane gas abundance profile measured by the Huygens Gas Chromatograph/Mass Spectrometer (GCMS). The visible and near-infrared spectrometers of th…
Suzaku broad-band spectroscopy of RX J1347.5-1145: constraints on the extremely hot gas and non-thermal emission
Yoshikawa, K.; Ota, N.; Komatsu, E. +6 more
Context: We present the results of our analysis of long Suzaku observations (149 ks and 122 ks for XIS and HXD, respectively) of the most X-ray luminous galaxy cluster, RX J1347.5-1145, at z=0.451.
Aims: To understand the gas physics of a violent, cluster merger, we study physical properties of the hot ( 20 keV) gas clump in the south-east (SE…
A New H I Survey of Active Galaxies
Ho, Luis C.; Greene, Jenny E.; Darling, Jeremy
We have conducted a new Arecibo survey for H I emission for 113 galaxies with broad-line (type 1) active galactic nuclei (AGNs) out to recession velocities as high as ~35,000 km s-1. The primary aim of the study is to obtain sensitive H I spectra for a well-defined, uniformly selected sample of active galaxies that have estimates of the…
Strongly Blueshifted Phenomena Observed with Hinode EIS in the 2006 December 13 Solar Flare
Culhane, J. L.; Hara, Hirohisa; Narukage, Noriyuki +5 more
We present a detailed examination of strongly blueshifted emission lines observed with the EUV Imaging Spectrometer on board the Hinode satellite. We found two kinds of blueshifted phenomenon associated with the X3.4 flare that occurred on 2006 December 13. One was related to a plasmoid ejection seen in soft X-rays. It was very bright in all the l…
Distribution of the ultraviolet nitric oxide Martian night airglow: Observations from Mars Express and comparisons with a one-dimensional model
Reberac, A.; Bertaux, J. -L.; Leblanc, F. +4 more
Limb observations with the SPICAM ultraviolet spectrometer on board the Mars Express orbiter revealed ultraviolet nightglow emission in the δ (190-240 nm) and γ (225-270 nm) bands of nitric oxide. This emission arises from radiative recombination between O(3P) and N(4S) atoms that are produced on the day side and form excited…
How rapidly do neutron stars spin at birth? Constraints from archival X-ray observations of extragalactic supernovae
Soria, Roberto; Stella, Luigi; Perna, Rosalba +1 more
Traditionally, studies aimed at inferring the distribution of birth periods of neutron stars are based on radio surveys. Here we propose an independent method to constrain the pulsar spin periods at birth based on their X-ray luminosities. In particular, the observed luminosity distribution of supernovae (SNe) poses a constraint on the initial rot…
HST ACS Imaging of M82: A Comparison of Mass and Size Distribution Functions of the Younger Nuclear and Older Disk Clusters
Luna, A.; Mayya, Y. D.; Rosa-González, D. +3 more
We present the results obtained from an objective search for stellar clusters, both in the currently active nuclear starburst region, and in the poststarburst disk of M82. Images obtained with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST) in F435W (B), F555W (V), and F814W (I) filters were used in the search for t…
On the radial distribution of white dwarfs in the globular cluster NGC 6397
Anderson, J.; Davis, D. S.; King, I. R. +5 more
We have examined the radial distribution of white dwarfs over a single Hubble Space Telescope/Advanced Camera for Surveys field in the nearby globular cluster NGC 6397. In relaxed populations, such as in a globular cluster, stellar velocity dispersion, and hence radial distribution, is directly dependent on stellar masses. The progenitors of very …