Search Publications
XMM-Newton and NuSTAR Simultaneous X-Ray Observations of IGR J11215-5952
Tiengo, A.; Sidoli, L.; Natalucci, L. +3 more
We report the results of an XMM-Newton and NuSTAR coordinated observation of the Supergiant Fast X-ray Transient (SFXT) IGR J11215-5952, performed on 2016 February 14, during the expected peak of its brief outburst, which repeats every ∼165 days. Timing and spectral analysis were performed simultaneously in the energy band 0.4-78 keV. A spin perio…
Molecular Gas Kinematics and Star Formation Properties of the Strongly-lensed Quasar Host Galaxy RXS J1131-1231
Riechers, Dominik A.; Pavesi, Riccardo; Leung, T. K. Daisy
We report observations of CO(J = 2 → 1) and {CO}(J=3\to 2) line emission toward the quadruply-lensed quasar RXS J1131-1231 at z = 0.654 obtained using the Plateau de Bure Interferometer (PdBI) and the Combined Array for Research in Millimeter-wave Astronomy (CARMA). Our lens modeling shows that the asymmetry in the double-horned CO(J = 2 → 1) line…
The 1.1 mm Continuum Survey of the Small Magellanic Cloud: Physical Properties and Evolution of the Dust-selected Clouds
Kohno, Kotaro; Yun, Min S.; Kawabe, Ryohei +18 more
The first 1.1 mm continuum survey toward the Small Magellanic Cloud (SMC) was performed using the AzTEC instrument installed on the ASTE 10 m telescope. This survey covered 4.5 deg2 of the SMC with 1σ noise levels of 5-12 mJy beam-1, and 44 extended objects were identified. The 1.1 mm extended emission has good spatial correl…
Are Complex Magnetic Field Structures Responsible for the Confined X-class Flares in Super Active Region 12192?
Li, Ting; Zhang, Jun; Chen, Huadong
From 2014 October 19 to 27, six X-class flares occurred in super active region (AR) 12192. They were all confined flares and were not followed by coronal mass ejections. To examine the structures of the four flares close to the solar disk center from October 22 to 26, we firstly employ composite triple-time images in each flare process to display …
Non-potential Field Formation in the X-shaped Quadrupole Magnetic Field Configuration
Shimizu, T.; Inoue, S.; Kawabata, Y.
Some types of solar flares are observed in X-shaped quadrupolar field configuration. To understand the magnetic energy storage in such a region, we studied non-potential field formation in an X-shaped quadrupolar field region formed in the active region NOAA 11967, which produced three X-shaped M-class flares on 2014 February 2. Nonlinear force-fr…
Angular Momentum Evolution of Young Stars in the nearby Scorpius-Centaurus OB Association
Oberst, Thomas E.; Mamajek, Eric E.; Mellon, Samuel N. +1 more
We report the results of a study of archival SuperWASP light curves for stars in Scorpius-Centaurus (Sco-Cen), the nearest OB association. We use SuperWASP time-series photometry to extract rotation periods for 189 candidate members of the Sco-Cen complex and verify that 162 of those are members of the classic Sco-Cen subgroups of Upper Scorpius (…
HST/COS Far-ultraviolet Spectroscopic Analysis of U Geminorum Following a Wide Outburst
Sion, Edward M.; Godon, Patrick; Shara, Michael M. +1 more
We used the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) to obtain a series of four far-ultraviolet (FUV; 915-2148 Å) spectroscopic observations of the prototypical dwarf nova U Geminorum during its cooling following a two-week outburst. Our FUV spectral analysis of the data indicates that the white dwarf (WD) cools from a…
The Unusually High Halo Concentration of the Fossil Group NGC 6482: Evidence for Weak Adiabatic Contraction
Buote, David A.
Although fossil galaxy systems are thought to be very old, and thus should possess above-average halo concentrations, typically fossils have unexceptional concentrations of their masses. We revisit the massive isolated elliptical galaxy/fossil group NGC 6482 for which previous X-ray studies of a modest Chandra observation obtained a very uncertain…
Phase Relations between the Sunspot Numbers and Total Solar Irradiance
Xu, J. C.; Xie, J. L.; Qu, Z. N.
Understanding the effect of sunspot activities on the variations in the total solar irradiance (TSI) is essential for the interpretation of the variability of TSI as well as its reconstruction. Phase relations between the sunspot numbers (SN) and two TSI composite data are investigated. It is found that TSI and SN are positively correlated, and th…
INTEGRAL Observations of GW170104
Sunyaev, R.; Hanlon, L.; Mereghetti, S. +16 more
We used data from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) to set upper limits on the γ-ray and hard X-ray prompt emission associated with the gravitational-wave event GW170104, discovered by the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo collaboration. The unique omnidirectional viewing capability of th…