Search Publications
Spatially radiative properties of 3C 58 and G21.5-0.9
Zhang, Li; Lu, Fang-Wu; Gao, Quan-Gui +1 more
Observations of two pulsar wind nebulae (PWNe) 3C 58 and G21.5-0.9 indicate that they have mostly symmetric spherical morphologies, emit photons from radio to γ-rays and have the radial variations of the photon indices in X-ray band. The spatially radiative properties of 3C 58 and G21.5-0.9 are modelled in the frame of a spatially dependent model.…
Precise CCD positions of Himalia using Gaia DR1 in 2015-2016
Wang, N.; Peng, Q. Y.; Peng, H. W.
In order to obtain high-precision CCD positions of Himalia, the sixth Jovian satellite, a total of 598 CCD observations have been obtained during the years 2015-2016. The observations were made by using the 2.4 and 1 m telescopes administered by Yunnan Observatories over 27 nights. Several factors that would influence the positional precision of H…
Infrared polarimetry of Mrk 231: scattering off hot dust grains in the central core
Siebenmorgen, R.; Telesco, C. M.; Packham, C. +13 more
We present high-angular (0.17-0.35 arcsec) resolution imaging polarimetric observations of Mrk 231 in the 3.1 µm filter using MMT-Pol on the 6.5-m MMT, and in the 8.7, 10.3, and 11.6 µm filters using CanariCam on the 10.4-m Gran Telescopio CANARIAS. In combination with already published observations, we compile the 1-12 µm total …
Chandra X-ray observations of the hyper-luminous infrared galaxy IRAS F15307+3252
Iwasawa, K.; Fabian, A. C.; Gandhi, P. +6 more
Hyper-luminous infrared galaxies (HyLIRGs) lie at the extreme luminosity end of the IR galaxy population with LIR > 1013 L⊙. They are thought to be closer counterparts of the more distant sub-millimeter galaxies, and should therefore be optimal targets to study the most massive systems in formation. We present d…
On the lensed blazar B0218+357
Falomo, R.; Treves, A.; Scarpa, R. +2 more
We present an optical spectrum (λλ4000-10 500) of the lensed blazar B0218+357 secured at the 10 m GTC and aimed to investigate and clarify the properties of this intriguing system. We found that the emission line spectrum of the blazar is characterized by only one broad emission line that interpreted as Mg II 2800 Å yields z = 0.95. In addition, w…
The M 4 Core Project with HST - V. Characterizing the PSFs of WFC3/UVIS by focus★
Anderson, J.; Bedin, L. R.
As part of the astrometric Hubble Space Telescope (HST) large program GO-12911, we conduct an in-depth study to characterize the point spread function (PSF) of the Uv-VISual channel of the Wide Field Camera 3 (WFC3), as a necessary step to achieve the astrometric goals of the program. We extracted a PSF from each of the 589 deep exposures taken th…
Deep Chandra observations of NGC 7457, the X-ray point source populations of a low-mass early-type galaxy
Kundu, Arunav; Zepf, Stephen E.; Maccarone, Thomas J. +4 more
We present the X-ray point source population of NGC 7457 based on 124 ks of Chandra observations. Previous deep Chandra observations of low-mass X-ray binaries (LMXBs) in early-type galaxies have typically targeted the large populations of massive galaxies. NGC 7457 is a nearby, early-type galaxy with a stellar luminosity of 1.7× 10^{10}{L_{K{⊙}}}…
A hierarchical model for the ages of Galactic halo white dwarfs
Si, Shijing; van Dyk, David A.; von Hippel, Ted +3 more
In astrophysics, we often aim to estimate one or more parameters for each member object in a population and study the distribution of the fitted parameters across the population. In this paper, we develop novel methods that allow us to take advantage of existing software designed for such case-by-case analyses to simultaneously fit parameters of b…
Herschel/SPIRE observations of water production rates and ortho-to-para ratios in comets★
Swinyard, Bruce M.; Wilson, Thomas G.; Rawlings, Jonathan M. C.
This paper presents Herschel/SPIRE (Spectral and Photometric Imaging Receiver) spectroscopic observations of several fundamental rotational ortho- and para-water transitions seen in three Jupiter-family comets and one Oort-cloud comet. Radiative transfer models that include excitation by collisions with neutrals and electrons, and by solar infrare…
The NGC 454 system: anatomy of a mixed ongoing merger
Plana, H.; Marino, A.; Mazzei, P. +3 more
This paper focuses on NGC 454, a nearby interacting pair of galaxies (AM 0112-554, RR23), composed of an early-type (NGC 454 E) and a star-forming late-type companion (NGC 454 W). We aim at characterizing this wet merger candidate via a multi-λ analysis, from near-UV (NUV) to optical using Swift UV/Optical Telescope (UVOT), and mapping the H α int…