Search Publications
Toward a Direct Measure of the Galactic Acceleration
De Rosa, Robert J.; Huber, Daniel; Rhode, Katherine L. +9 more
High-precision spectrographs can enable not only the discovery of exoplanets, but can also provide a fundamental measurement in Galactic dynamics. Over about 10 year baselines, the expected change in the line-of-sight velocity due to the Galaxy's gravitational field for stars at ∼kiloparsec scale distances above the Galactic midplane is ∼few tens …
Hard X-ray selected giant radio galaxies - II. Morphological evidence of restarted radio activity
Venturi, T.; Dallacasa, D.; Ubertini, P. +10 more
About 6 per cent of radio galaxies (RGs) can reach linear sizes larger than 0.7 Mpc, and are then classified as giant radio galaxies (GRGs). The conditions that make possible the formation of such big structures are still not clear - either core accretion properties or environmental factors. Recent studies have shown that GRGs can be up to four ti…
A thin shell of ionized gas as the explanation for infrared excess among classical Cepheids
Kervella, P.; Domiciano de Souza, A.; Marengo, M. +12 more
Context. The infrared (IR) excess of classical Cepheids is seldom studied and poorly understood despite observational evidence and the potential for its contribution to induce systematics on the period-luminosity (PL) relation used in the calibration of the extragalactic distance scale.
Aims: This study aims to understand the physical origin …
Mapping Outflowing Gas in the Fermi Bubbles: A UV Absorption Survey of the Galactic Nuclear Wind
Jenkins, Edward B.; Savage, Blair D.; Lockman, Felix J. +5 more
Using new ultraviolet (UV) spectra of five background quasars from the Cosmic Origins Spectrograph on the Hubble Space Telescope, we analyze the low-latitude ( $| b| =20^\circ \mbox{--}30^\circ $ ) regions of the Fermi Bubbles, the giant gamma-ray-emitting lobes at the Galactic Center. We combine these data with previous UV and atomic hydrogen (H …
CTCV J2056-3014: An X-Ray-faint Intermediate Polar Harboring an Extremely Fast-spinning White Dwarf
Mukai, K.; Oliveira, A. S.; Rodrigues, C. V. +2 more
We report on XMM-Newton X-ray observations that reveal CTCV J2056-3014 to be an unusual accretion-powered, intermediate polar (IP) system. It is a member of the class of X-ray-faint IPs whose space density remains unconstrained but potentially very high, with Lx,0.3-12 keV of 1.8 × 1031 erg s-1. We discovered a coh…
Radio observations of magnetic cataclysmic variables
Mason, Paul A.; Singh, Kulinder P.; Barrett, Paul +2 more
The NSF's Karl G. Jansky Very Large Array (VLA) is used to observe 122 magnetic cataclysmic variables (MCVs) during three observing semesters (13B, 15A, and 18A). We report radio detections of 33 stars with fluxes in the range 6-8031 µJy. Twenty-eight stars are new radio sources, increasing the number of radio detected MCVs to more that 40. …
Power of halometry
Van Tilburg, Ken; Weiner, Neal; Mishra-Sharma, Siddharth
Astrometric weak gravitational lensing is a powerful probe of the distribution of matter on sub-Galactic scales, which harbor important information about the fundamental nature of dark matter. We propose a novel method that utilizes angular power spectra to search for the correlated pattern of apparent motions of celestial objects induced from tim…
Searching for molecular gas inflows and outflows in the nuclear regions of five Seyfert galaxies
Rigopoulou, D.; Domínguez-Fernández, A. J.; García-Burillo, S. +8 more
Active galactic nucleus (AGN) driven outflows are believed to play an important role in regulating the growth of galaxies, mostly via negative feedback. However, their effects on their hosts are far from clear, especially for low- and moderate-luminosity Seyferts. To investigate this issue, we obtained cold molecular gas observations, traced by th…
Lens modelling of the strongly lensed Type Ia supernova iPTF16geu
Goldstein, D. A.; Amanullah, R.; Goobar, A. +3 more
In 2016, the first strongly lensed Type Ia supernova (SN Ia), iPTF16geu, at redshift z = 0.409 with four resolved images arranged symmetrically around the lens galaxy at z = 0.2163, was discovered. Here, refined observations of iPTF16geu, including the time delay between images, are used to decrease uncertainties in the lens model, including the t…
Evidence for a Coronal Shock Wave Origin for Relativistic Protons Producing Solar Gamma-Rays and Observed by Neutron Monitors at Earth
Kouloumvakos, Athanasios; Rouillard, Alexis P.; Papaioannou, Athanasios +4 more
We study the solar eruptive event on 2017 September 10 that produced long-lasting >100 MeV γ-ray emission and a ground level enhancement (GLE72). The origin of the high-energy ions producing late-phase gamma-ray emission (LPGRE) is still an open question, but a possible explanation is proton acceleration at coronal shocks produced by coronal ma…