Search Publications
X-ray absorption towards high-redshift sources: probing the intergalactic medium with blazars
Campana, S.; Ghisellini, G.; Salvaterra, R. +1 more
The role played by the intergalactic medium (IGM) in the X-ray absorption towards high-redshift sources has recently drawn more attention in spectral analysis studies. Here, we study the X-ray absorption towards 15 flat-spectrum radio quasars at z > 2, relying on high counting statistic (≳10 000 photons) provided by XMM-Newton, with additional …
Multi-epoch analysis of the X-ray spectrum of the active galactic nucleus in NGC 5506
Ni, Qingling; Bambi, Cosimo; Guainazzi, Matteo +5 more
We present a multi-epoch X-ray spectroscopy analysis of the nearby narrow-line Seyfert I galaxy NGC 5506. For the first time, spectra taken by Chandra, XMM-Newton, Suzaku, and NuSTAR- covering the 2000-2014 time span - are analysed simultaneously, using state-of-the-art models to describe reprocessing of the primary continuum by optical thick matt…
HST imaging of four gravitationally lensed quasars
King, A. L.; Barone-Nugent, R. L.; Bate, N. F. +7 more
We present new Hubble Space Telescope WFC3 imaging of four gravitationally lensed quasars: MG 0414+0534; RXJ 0911+0551; B 1422+231; WFI J2026-4536. In three of these systems we detect wavelength-dependent microlensing, which we use to place constraints on the sizes and temperature profiles of the accretion discs in each quasar. Accretion disc radi…
The Second Data Release of the Beijing-Arizona Sky Survey
Myers, Adam D.; Fan, Xiaohui; Jiang, Linhua +29 more
This paper describes the second data release (DR2) of the Beijing-Arizona Sky Survey (BASS). BASS is an imaging survey covering a 5400 deg2 footprint in the g and r bands using the 2.3 m Bok telescope. DR2 includes the observations through 2017 July obtained by BASS and by the Mayall z-band Legacy Survey (MzLS), which used the 4 m Mayal…
A direct measure of free electron gas via the kinematic Sunyaev-Zel'dovich effect in Fourier-space analysis
Spergel, David N.; Okumura, Teppei; Sugiyama, Naonori S.
We present the measurement of the kinematic Sunyaev-Zel'dovich (kSZ) effect in Fourier space, rather than in real space. We measure the density-weighted pairwise kSZ power spectrum, the first use of this promising approach, by cross-correlating a cleaned cosmic microwave background (CMB) temperature map, which jointly uses both Planck Release 2 an…
An explanation for the gap in the Gaia HRD for M dwarfs
Gizis, John; MacDonald, James
We show that the recently discovered narrow gap in the Gaia Hertzsprung-Russell Diagram near MG = 10 can be explained by standard stellar evolution models and results from a dip in the luminosity function associated with mixing of 3He during merger of envelope and core convection zones that occurs for a narrow range of masses.
A Solar Stationary Type IV Radio Burst and Its Radiation Mechanism
Koval, Artem; Chen, Yao; Feng, Shiwei +6 more
A stationary Type IV (IVs) radio burst was observed on September 24, 2011. Observations from the Nançay RadioHeliograph (NRH) show that the brightness temperature (TB) of this burst is extremely high, over 1011 K at 150 MHz and over 108 K in general. The degree of circular polarization (q ) is between −60 % ∼−100 %…
Discovery of an Extremely Luminous Dust-obscured Galaxy Observed with SDSS, WISE, JCMT, and SMA
Ueda, Junko; Kawabe, Ryohei; Saito, Toshiki +5 more
We present the discovery of an extremely luminous dust-obscured galaxy (DOG) at z spec = 3.703, WISE J101326.25+611220.1. This DOG is selected as a candidate of extremely luminous infrared (IR) galaxies based on the photometry from the Sloan Digital Sky Survey and Wide-field Infrared Survey Explorer. In order to derive its accurate IR l…
Gaia DR2 view of the Lupus V-VI clouds: The candidate diskless young stellar objects are mainly background contaminants
Prusti, T.; Fedele, D.; Alcalá, J. M. +10 more
Extensive surveys of star-forming regions with Spitzer have revealed populations of disk-bearing young stellar objects. These have provided crucial constraints, such as the timescale of dispersal of protoplanetary disks, obtained by carefully combining infrared data with spectroscopic or X-ray data. While observations in various regions agree with…
Comparison of Dust Impact and Solitary Wave Signatures Detected by Multiple Electric Field Antennas Onboard the MMS Spacecraft
Mann, Ingrid; Vaverka, Jakub; Pellinen-Wannberg, Asta +6 more
Dust impact detection by electric field instruments is a relatively new method. However, the influence of dust impacts on electric field measurements is not completely understood and explained. A better understanding is very important for reliable dust impact identification, especially in environments with low dust impact rate. Using data from Ear…