Search Publications
NuSTAR and XMM-Newton Observations of the Extreme Ultraluminous X-Ray Source NGC 5907 ULX1: A Vanishing Act
Harrison, F. A.; Stern, D.; Bachetti, M. +15 more
We present results obtained from two broadband X-ray observations of the extreme ultraluminous X-ray source (ULX) NGC 5907 ULX1, known to have a peak X-ray luminosity of ~5 × 1040 erg s-1. These XMM-Newton and NuSTAR observations, separated by only ~4 days, revealed an extreme level of short-term flux variability. In the firs…
New Ultraviolet Extinction Curves for Interstellar Dust in M31
Gordon, Karl D.; Fitzpatrick, Edward L.; Bohlin, R. C. +4 more
New low-resolution UV spectra of a sample of reddened OB stars in M31 were obtained with the Hubble Space Telescope/STIS to study the wavelength dependence of interstellar extinction and the nature of the underlying dust grain populations. Extinction curves were constructed for four reddened sightlines in M31 paired with closely matching stellar a…
Herschel Galactic Plane Survey of [NII] Fine Structure Emission
Goldsmith, Paul F.; Pineda, Jorge L.; Yıldız, Umut A. +1 more
We present the first large-scale high angular resolution survey of ionized nitrogen in the Galactic Plane through emission of its two fine structure transitions ([N ii]) at 122 and 205 µm. The observations were largely obtained with the PACS instrument onboard the Herschel Space Observatory. The lines of sight were in the Galactic plane, fol…
ALMA imaging of SDP.81 - II. A pixelated reconstruction of the CO emission lines
Andreani, P.; Rybak, M.; Vegetti, S. +2 more
We present a sub-100 pc-scale analysis of the CO molecular gas emission and kinematics of the gravitational lens system SDP.81 at redshift 3.042 using Atacama Large Millimetre/submillimetre Array (ALMA) science verification data and a visibility-plane lens reconstruction technique. We find clear evidence for an excitation-dependent structure in th…
Neutrinos in the holographic dark energy model: constraints from latest measurements of expansion history and growth of structure
Zhang, Jing-Fei; Zhang, Xin; Li, Yun-He +1 more
The model of holographic dark energy (HDE) with massive neutrinos and/or dark radiation is investigated in detail. The background and perturbation evolutions in the HDE model are calculated. We employ the PPF approach to overcome the gravity instability difficulty (perturbation divergence of dark energy) led by the equation-of-state parameter w ev…
The resolved star-formation relation in nearby active galactic nuclei
Combes, Françoise; Casasola, Viviana; Hunt, Leslie +1 more
Aims: We present an analysis of the relation between the star formation rate (SFR) surface density (ΣSFR) and mass surface density of molecular gas (ΣH2), commonly referred to as the Kennicutt-Schmidt (K-S) relation, on its intrinsic spatial scale, i.e. the size of giant molecular clouds (~10-150 pc), in the c…
The Galactic 26Al Emission Map as Revealed by INTEGRAL SPI
Jourdain, Elisabeth; Roques, Jean-Pierre; Bouchet, Laurent
Diffuse emission is often challenging since it is undetectable by most instruments, which are generally dedicated to point-source studies. The 26Al emission is a good illustration: the only available 26Al map to date has been released, more than 15 yr ago, thanks to the COMPTEL instrument. However, at the present time, the SP…
Systematic analysis of occurrence of equatorial noise emissions using 10 years of data from the Cluster mission
Santolík, O.; Němec, F.; Cornilleau-Wehrlin, N. +2 more
We report results of a systematic analysis of equatorial noise (EN) emissions which are also known as fast magnetosonic waves. EN occurs in the vicinity of the geomagnetic equator at frequencies between the local proton cyclotron frequency and the lower hybrid frequency. Our analysis is based on the data collected by the Spatio-Temporal Analysis o…
The Inner Disk Structure, Disk-Planet Interactions, and Temporal Evolution in the β Pictoris System: A Two-epoch HST/STIS Coronagraphic Study
Schneider, Glenn; Apai, Dániel; Wyatt, Mark C. +5 more
We present deep Hubble Space Telescope/Space Telescope Imaging Spectrograph coronagraphic images of the β Pic debris disk obtained at two epochs separated by 15 yr. The new images and the re-reduction of the 1997 data provide the most sensitive and detailed views of the disk at optical wavelengths as well as the yet smallest inner working angle op…
A Luminous Red Nova in M31 and its Progenitor System
Steele, I. A.; Bode, M. F.; Darnley, M. J. +1 more
We present observations of M31LRN 2015 (MASTER OT J004207.99+405501.1), discovered in M31 in 2015 January, and identified as a rare and enigmatic luminous red nova (LRN). Spectroscopic and photometric observations obtained by the Liverpool Telescope showed the LRN becoming extremely red as it faded from its {{M}V}=-9.4+/- 0.2 peak. Earl…