Search Publications
Spectral State Dependence of the 0.4-2 MeV Polarized Emission in Cygnus X-1 Seen with INTEGRAL/IBIS, and Links with the AMI Radio Data
Grinberg, Victoria; Pottschmidt, Katja; Wilms, Jörn +6 more
Polarization of the ≳ 400 keV hard tail of the microquasar Cygnus X-1 has been independently reported by INTEGRAL/Imager on Board the INTEGRAL Satellite (IBIS), and INTEGRAL/SPectrometer on INTEGRAL and interpreted as emission from a compact jet. These conclusions were, however, based on the accumulation of all INTEGRAL data regardless of the spec…
A Uniform Contribution of Core-collapse and Type Ia Supernovae to the Chemical Enrichment Pattern in the Outskirts of the Virgo Cluster
Simionescu, A.; Allen, S. W.; Werner, N. +3 more
We present the first measurements of the abundances of α-elements (Mg, Si, and S) extending out beyond the virial radius of a cluster of galaxies. Our results, based on Suzaku Key Project observations of the Virgo Cluster, show that the chemical composition of the intracluster medium is consistent with being constant on large scales, with a flat d…
The Progenitor of the Type IIb SN 2008ax Revisited
Nomoto, Ken'ichi; Folatelli, Gastón; Kuncarayakti, Hanindyo +3 more
Hubble Space Telescope observations of the site of the supernova (SN) SN 2008ax obtained in 2011 and 2013 reveal that the possible progenitor object detected in pre-explosion images was in fact multiple. Four point sources are resolved in the new, higher-resolution images. We identify one of the sources with the fading SN. The other three objects …
Imaging and Spectral Observations of Quasi-periodic Pulsations in a Solar Flare
Li, D.; Zhang, Q. M.; Ning, Z. J.
We explore the quasi-periodic pulsations (QPPs) in a solar flare observed by Fermi Gamma-ray Burst Monitor, Solar Dynamics Observatory, Solar Terrestrial Relations Observatory, and Interface Region Imaging Spectrograph (IRIS) on 2014 September 10. QPPs are identified as the regular and periodic peaks on the rapidly varying components, which are th…
The Destruction of the Circumstellar Ring of SN 1987A
Smith, Nathan; Garnavich, Peter; Pun, Chun S. J. +23 more
We present imaging and spectroscopic observations with Hubble Space Telescope and Very Large Telescope of the ring of SN 1987A from 1994 to 2014. After an almost exponential increase of the shocked emission from the hotspots up to day ∼8000 (∼2009), both this and the unshocked emission are now fading. From the radial positions of the hotspots we s…
Does the Presence of Planets Affect the Frequency and Properties of Extrasolar Kuiper Belts? Results from the Herschel Debris and Dunes Surveys
Duchêne, G.; Eiroa, C.; Marshall, J. P. +14 more
The study of the planet-debris disk connection can shed light on the formation and evolution of planetary systems and may help “predict” the presence of planets around stars with certain disk characteristics. In preliminary analyses of subsamples of the Herschel DEBRIS and DUNES surveys, Wyatt et al. and Marshall et al. identified a tentative corr…
Quasi-periodic Fluctuations and Chromospheric Evaporation in a Solar Flare Ribbon Observed by IRIS
Brosius, Jeffrey W.; Daw, Adrian N.
The Interface Region Imaging Spectrograph (IRIS) satellite obtained rapid cadence (9.4 s) stare spectra of an M7 flare ribbon in AR 12036 on 2014 April 18. Chromospheric and transition region line emission exhibited quasi-periodic intensity and velocity fluctuations in the ribbon prior to the appearance of Fe xxi emission. Seven intensity peaks we…
The Grism Lens-amplified Survey from Space (GLASS). IV. Mass Reconstruction of the Lensing Cluster Abell 2744 from Frontier Field Imaging and GLASS Spectroscopy
Vulcani, B.; Hoag, A.; Bradač, M. +12 more
We present a strong and weak lensing reconstruction of the massive cluster Abell 2744, the first cluster for which deep Hubble Frontier Fields (HFF) images and spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) are available. By performing a targeted search for emission lines in multiply imaged sources using the GLASS spectra, we…
Revised Lens Model for the Multiply Imaged Lensed Supernova, “SN Refsdal” in MACS J1149+2223
Sharon, Keren; Johnson, Traci L.
We present a revised lens model of MACS J1149+2223, in which the first resolved multiply imaged lensed supernova (SN) was discovered. The lens model is based on the model of Johnson et al. with some modifications. We include more lensing constraints from the host galaxy of the newly discovered SN, and increase the flexibility of the model in order…
A Consistent Picture Emerges: A Compact X-Ray Continuum Emission Region in the Gravitationally Lensed Quasar SDSS J0924+0219
Kochanek, C. S.; Dai, X.; Chartas, G. +7 more
We analyze the optical, UV, and X-ray microlensing variability of the lensed quasar SDSS J0924+0219 using six epochs of Chandra data in two energy bands (spanning 0.4-8.0 keV, or 1-20 keV in the quasar rest frame), 10 epochs of F275W (rest-frame 1089 Å) Hubble Space Telescope data, and high-cadence R-band (rest-frame 2770 Å) monitoring spanning 11…