Search Publications
A Possible Ultra Strong and Broad Fe Kα Emission Line in Seyfert 2 Galaxy IRAS 00521-7054
Shu, X. W.; Wang, J. X.; Tan, Y. +1 more
We present XMM-Newton spectra of the Seyfert 2 Galaxy IRAS 00521-7054. A strong feature at ~6 keV (observer's frame) can be formally fitted with a strong (EW = 1.3 ± 0.3 keV in the rest frame) and broad Fe Kα line, extending down to 3 keV. The underlying X-ray continuum could be fitted with an absorbed power law (with Γ = 1.8 ± 0.2 and N H
On the Shapes and Structures of High-redshift Compact Galaxies
Glazebrook, Karl; Chevance, Mélanie; Abraham, Roberto G. +5 more
Recent deep Hubble Space Telescope WFC3 imaging suggests that a majority of compact quiescent massive galaxies at z ~ 2 may contain disks. To investigate this claim, we have compared the ellipticity distribution of 31 carefully selected high-redshift massive quiescent compact galaxies to a set of mass-selected ellipticity and Sérsic index distribu…
AE Aurigae: First Detection of Non-thermal X-Ray Emission from a Bow Shock Produced by a Runaway Star
Miceli, M.; Bonito, R.; Romero, G. E. +6 more
Runaway stars produce shocks when passing through interstellar medium at supersonic velocities. Bow shocks have been detected in the mid-infrared for several high-mass runaway stars and in radio waves for one star. Theoretical models predict the production of high-energy photons by non-thermal radiative processes in a number sufficiently large to …
Direct Measurement of the X-Ray Time-delay Transfer Function in Active Galactic Nuclei
Turner, T. J.; Kraemer, S. B.; Reeves, J. N. +3 more
The origin of the observed time lags, in nearby active galactic nuclei (AGNs), between hard and soft X-ray photons is investigated using new XMM-Newton data for the narrow-line Seyfert I galaxy Ark 564 and existing data for 1H 0707-495 and NGC 4051. These AGNs have highly variable X-ray light curves that contain frequent, high peaks of emission. T…
Spectroscopic Confirmation of a z = 6.740 Galaxy behind the Bullet Cluster
Fontana, Adriano; Stiavelli, Massimo; Treu, Tommaso +7 more
We present the first results of our spectroscopic follow-up of 6.5 < z < 10 candidate galaxies behind clusters of galaxies. We report the spectroscopic confirmation of an intrinsically faint Lyman break galaxy (LBG) identified as a z 850LP-band dropout behind the Bullet Cluster. We detect an emission line at λ = 9412 Å at >5σ s…
A KS and IRAC Selection of High-redshift Extremely Red Objects
Wang, Wei-Hao; Cowie, Lennox L.; Barger, Amy J.
In order to find the most extreme dust-hidden high-redshift galaxies, we select 196 extremely red objects in the KS and Infrared Array Camera (IRAC) bands (KIEROs, [Ks - 4.5 µm]AB > 1.6) in the 0.06 deg2 Great Observatories Origins Deep Surveys-North (GOODS-N) region. This selection avoids the B…
Spectroscopic Observations of Fe XVIII in Solar Active Regions
Teriaca, Luca; Warren, Harry P.; Curdt, Werner
The large uncertainties associated with measuring the amount of high temperature emission in solar active regions (ARs) represents a significant impediment to making progress on the coronal heating problem. Most current observations at temperatures of 3 MK and above are taken with broadband soft X-ray instruments. Such measurements have proven dif…
The 21 cm "Outer Arm" and the Outer-galaxy High-velocity Clouds: Connected by Kinematics, Metallicity, and Distance
Tripp, Todd M.; Song, Limin
Using high-resolution ultraviolet spectra obtained with the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Far Ultraviolet Spectroscopic Explorer, we study the metallicity, kinematics, and distance of the gaseous "outer arm" (OA) and the high-velocity clouds (HVCs) in the outer Galaxy. We detect the OA in a variety of absorpti…
Temperature and Extreme-ultraviolet Intensity in a Coronal Prominence Cavity and Streamer
Landi, E.; Gibson, S. E.; Kucera, T. A. +2 more
We analyze the temperature and EUV line emission of a coronal cavity and surrounding streamer in terms of a morphological forward model. We use a series of iron line ratios observed with the Hinode Extreme-ultraviolet Imaging Spectrograph (EIS) on 2007 August 9 to constrain temperature as a function of altitude in a morphological forward model of …
HST and Optical Data Reveal White Dwarf Cooling, Spin, and Periodicities in GW Librae 3-4 Years after Outburst
Hermes, J. J.; Winget, D. E.; Szkody, Paula +9 more
Since the large amplitude 2007 outburst which heated its accreting, pulsating white dwarf, the dwarf nova system GW Librae has been cooling to its quiescent temperature. Our Hubble Space Telescope ultraviolet spectra combined with ground-based optical coverage during the third and fourth year after outburst show that the fluxes and temperatures ar…