Search Publications
Magnetar-like X-Ray Bursts Suppress Pulsar Radio Emission
Israel, G.; Kerr, M.; Rea, N. +9 more
Rotation-powered pulsars and magnetars are two different observational manifestations of neutron stars: rotation-powered pulsars are rapidly spinning objects that are mostly observed as pulsating radio sources, while magnetars, neutron stars with the highest known magnetic fields, often emit short-duration X-ray bursts. Here, we report simultaneou…
A Search for Spectral Hysteresis and Energy-dependent Time Lags from X-Ray and TeV Gamma-Ray Observations of Mrk 421
Maraschi, L.; Covino, S.; Antonelli, L. A. +222 more
Blazars are variable emitters across all wavelengths over a wide range of timescales, from months down to minutes. It is therefore essential to observe blazars simultaneously at different wavelengths, especially in the X-ray and gamma-ray bands, where the broadband spectral energy distributions usually peak. In this work, we report on three “targe…
A First Comparison of Millimeter Continuum and Mg II Ultraviolet Line Emission from the Solar Chromosphere
De Pontieu, B.; Schmit, D.; Leenaarts, J. +4 more
We present joint observations of the Sun by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph (IRIS). Both millimeter/submillimeter-λ continuum emission and ultraviolet (UV) line emission originate from the solar chromosphere and both have the potential to serve as powerful and complementary diag…
Star Formation at z = 2.481 in the Lensed Galaxy SDSS J1110 = 6459. I. Lens Modeling and Source Reconstruction
Rigby, Jane R.; Florian, Michael; Whitaker, Katherine E. +6 more
Using the combined resolving power of the Hubble Space Telescope and gravitational lensing, we resolve star-forming structures in a z∼ 2.5 galaxy on scales much smaller than the usual kiloparsec diffraction limit of HST. SGAS J111020.0+645950.8 is a clumpy, star-forming galaxy lensed by the galaxy cluster SDSS J1110+6459 at z=0.659, with a total m…
The “UV-route” to Search for Blue Straggler Stars in Globular Clusters: First Results from the HST UV Legacy Survey
Dalessandro, E.; Nardiello, D.; Vesperini, E. +4 more
We used data from the Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters to select the Blue Straggler Star (BSS) population in four intermediate/high density systems (namely NGC 2808, NGC 6388, NGC 6541, and NGC 7078) through a “UV-guided search.” This procedure consists of using the F275W images in each cluster to construct the…
Importance of CME Radial Expansion on the Ability of Slow CMEs to Drive Shocks
Lugaz, Noé; Farrugia, Charles J.; Winslow, Reka M. +3 more
Coronal mass ejections (CMEs) may disturb the solar wind by overtaking it or expanding into it, or both. CMEs whose front moves faster in the solar wind frame than the fast magnetosonic speed drive shocks. Such shocks are important contributors to space weather, by triggering substorms, compressing the magnetosphere, and accelerating particles. In…
Exploring the Inner Acceleration Region of Solar Wind: A Study Based on Coronagraphic UV and Visible Light Data
Bemporad, A.
This work combined coronagraphic visible light (VL) and UV data to provide with an unprecedented view of the inner corona where the nascent solar wind is accelerated. The UV (H I Lyα) and VL (polarized brightness) images (reconstructed with SOHO/UVCS, LASCO, and Mauna Loa data) have been analyzed with the Doppler dimming technique to provide for t…
Specific Frequencies and Luminosity Profiles of Cluster Galaxies and Intracluster Light in Abell 1689
Blakeslee, J. P.; Alamo-Martínez, K. A.
We present magnitudes and profile fits for 180 galaxies in the central field of the massive lensing cluster Abell 1689 using very deep imaging with the Hubble Space Telescope Advanced Camera for Surveys in the F814W bandpass. Previous work revealed an exceptionally large number of globular clusters (GCs) in A1689 and mapped their number density di…
Photometric Determination of the Mass Accretion Rates of Pre-main-sequence Stars. V. Recent Star Formation in the 30 Dor Nebula
Panagia, Nino; Beccari, Giacomo; De Marchi, Guido
We report on the properties of the low-mass stars that recently formed in the central ∼ 2\buildrel{ \prime}\over{.} 7× 2\buildrel{ \prime}\over{.} 7 of 30 Dor, including the R136 cluster. Using the photometric catalog of De Marchi et al., based on observations with the Hubble Space Telescope, and the most recent extinction law for this field, we i…
Shedding Light on the Compton-thick Active Galactic Nucleus in the Ultraluminous Infrared Galaxy UGC 5101 with Broadband X-Ray Spectroscopy
Imanishi, Masatoshi; Tanimoto, Atsushi; Ueda, Yoshihiro +3 more
We report the broadband X-ray spectra of the ultraluminous infrared galaxy (ULIRG) UGC 5101 in the 0.25-100 keV band observed with the Swift/Burst Alert Telescope (BAT), Nuclear Spectroscopic Telescope Array (NuSTAR), Suzaku, XMM-Newton, and Chandra. A Compton-thick active galactic nucleus (AGN) obscured with a hydrogen column density of ≈ 1.3× {1…