Search Publications
Five New INTEGRAL Unidentified Hard X-ray Sources Uncovered by Chandra
Capitanio, F.; Bird, A. J.; Fiocchi, M. +4 more
The IBIS imager on board INTEGRAL, with a sensitivity better than a milliCrab in deep observations and a point-source location accuracy on the order of few arcminutes, has thus far localized 723 hard X-ray sources in the 17-100 keV energy band, of which about 1/3 are still unclassified. The aim of this paper is to provide subarcsecond localization…
Shocks and a Giant Planet in the Disk Orbiting BP Piscium?
Melis, C.; Zuckerman, B.; Song, Inseok +3 more
Spitzer Infrared Spectrograph data support the interpretation that BP Piscium, a gas and dust enshrouded star residing at high Galactic latitude, is a first-ascent giant rather than a classical T Tauri star. Our analysis suggests that BP Piscium's spectral energy distribution can be modeled as a disk with a gap that is opened by a giant planet. Mo…
Dust Abundance and Properties in the Nearby Dwarf Galaxies NGC 147 and NGC 185
Noriega-Crespo, Alberto; Marleau, Francine R.; Misselt, Karl A.
We present new mid- to far-infrared images of the two dwarf compact elliptical galaxies that are satellites of M31, NGC 185, and NGC 147, obtained with the Spitzer Space Telescope. Spitzer's high sensitivity and spatial resolution enable us for the first time to look directly into the detailed spatial structure and properties of the dust in these …
RR Lyrae Variables in the Local Group Dwarf Galaxy NGC 147
Yang, S. -C.; Sarajedini, Ata
We investigate the RR Lyrae (RRL) population in NGC 147, a dwarf satellite galaxy of M31 (Andromeda). We used both Thuan-Gunn g-band ground-based photometry from the literature and Hubble Space Telescope Wide Field Planetary Camera 2 archival data in the F555W and F814W passbands to investigate the pulsation properties of RRL variable candidates i…
Hydrogen Permitted Lines in the First Near-IR Spectra of Th 28 Microjet: Accretion or Ejection Tracers?
Nisini, Brunella; Bacciotti, Francesca; Coffey, Deirdre +1 more
We report the first near-infrared detection of the bipolar microjet from T Tauri star ThA 15-28 (hereafter Th 28). Spectra were obtained with Very Large Telescope (VLT)/ISAAC for the slit both perpendicular and parallel to the flow to examine jet kinematics and gas physics within the first arcsecond from the star. The jet was successfully detected…
Observations of the Optical Transient in NGC 300 with AKARI/IRC: Possibilities of Asymmetric Dust Formation
Tanaka, M.; Matsuhara, H.; Nakagawa, T. +10 more
We present the results of near-infrared (NIR) multi-epoch observations of the optical transient in the nearby galaxy NGC 300 (NGC 300-OT) at 398 and 582 days after the discovery with the Infrared Camera (IRC) on board AKARI. NIR spectra (2-5 µm) of NGC 300-OT were obtained for the first time. They show no prominent emission nor absorption fe…
Suzaku Observation of Strong Fluorescent Iron Line Emission from the Young Stellar Object V1647 ORI During its New X-ray Outburst
Hamaguchi, Kenji; Kastner, Joel H.; Richmond, Michael +2 more
The Suzaku X-ray satellite observed the young stellar object (YSO) V1647 Ori on 2008 October 8 during the new mass accretion outburst reported in 2008 August. During the 87 ks observation with a net exposure of 40 ks, V1647 Ori showed a high level of X-ray emission with a gradual decrease in flux by a factor of 5 and then displayed an abrupt flux …
Searching for X-ray Variability in the Glitching Anomalous X-ray Pulsar 1E 1841-045 in Kes 73
Zhu, Weiwei; Kaspi, Victoria M.
Anomalous X-ray pulsars (AXPs) are now established to exhibit significant X-ray variability and be prolific glitchers, with some glitches being accompanied by large radiative changes. An open issue is whether AXP glitches are generically accompanied by radiative changes, relevant for understanding magnetar physical properties. Here we report on an…
The Search for Planetary Mass Companions to Field Brown Dwarfs with HST/NICMOS
Bouy, H.; Henning, Th.; Brandner, W. +4 more
We present the results of a high-resolution spectral differential imaging survey of 12 nearby, relatively young field L dwarfs (<=1 Gyr) carried out with the Hubble Space Telescope/NICMOS to search for planetary mass companions at small physical separations from their host. The survey resolved two brown dwarf binaries: the L dwarf system Kelu-1…
Broadband Suzaku Observations of IGR J16207-5129
Chaty, S.; Tomsick, J. A.; Rodriguez, J. +3 more
An analysis of IGR J16207-5129 is presented based on observations taken with Suzaku. The data set represents ~80 ks of effective exposure time in a broad energy range between 0.5 and 60 keV, including unprecedented spectral sensitivity above 15 keV. The average source spectrum is well described by an absorbed power law in which we measured a large…