Search Publications
A likely decade-long sustained tidal disruption event
Ramirez-Ruiz, Enrico; Gwyn, Stephen D. J.; Komossa, S. +11 more
Multiwavelength flares from tidal disruption and accretion of stars can be used to find and study otherwise dormant massive black holes in galactic nuclei 1 . Previous well-monitored candidate flares were short-lived, with most emission confined to within ∼1 year 2-5 . Here we report the discovery of a well-observed super-lon…
Pre-inflationary universe in loop quantum cosmology
Zhu, Tao; Wang, Anzhong; Cleaver, Gerald +2 more
The evolutions of the flat Friedmann-Lemaître-Robertson-Walker universe and its linear perturbations are studied systematically in the dressed metric approach of loop quantum cosmology. When it is dominated by the kinetic energy of the inflaton at the quantum bounce, the evolution of the background can be divided into three different phases prior …
Molecular Gas Dominated 50 kpc Ram Pressure Stripped Tail of the Coma Galaxy D100
Yoshida, Michitoshi; Combes, Françoise; Sun, Ming +6 more
We have discovered large amounts of molecular gas, as traced by CO emission, in the ram pressure stripped gas tail of the Coma cluster galaxy D100 (GMP 2910), out to large distances of about 50 kpc. D100 has a 60 kpc long, strikingly narrow tail, which is bright in X-rays and Hα. Our observations with the IRAM 30 m telescope reveal in total ∼ {10}…
KELT-20b: A Giant Planet with a Period of P ∼ 3.5 days Transiting the V ∼ 7.6 Early A Star HD 185603
Bieryla, Allyson; Latham, David W.; Quinn, Samuel N. +54 more
We report the discovery of KELT-20b, a hot Jupiter transiting a V∼ 7.6 early A star, HD 185603, with an orbital period of P≃ 3.47 days. Archival and follow-up photometry, Gaia parallax, radial velocities, Doppler tomography, and AO imaging were used to confirm the planetary nature of KELT-20b and characterize the system. From global modeling we in…
GASP. III. JO36: A Case of Multiple Environmental Effects at Play?
Charlot, Stéphane; Fritz, Jacopo; Vulcani, Benedetta +12 more
The so-called jellyfish galaxies are objects exhibiting disturbed morphology, mostly in the form of tails of gas stripped from the main body of the galaxy. Several works have strongly suggested ram pressure stripping to be the mechanism driving this phenomenon. Here, we focus on one of these objects, drawn from a sample of optically selected jelly…
A cut-off in the TeV gamma-ray spectrum of the SNR Cassiopeia A
Maraschi, L.; Covino, S.; Antonelli, L. A. +140 more
It is widely believed that the bulk of the Galactic cosmic rays is accelerated in supernova remnants (SNRs). However, no observational evidence of the presence of particles of PeV energies in SNRs has yet been found. The young historical SNR Cassiopeia A (Cas A) appears as one of the best candidates to study acceleration processes. Between 2014 De…
Observational constraints on the specific accretion-rate distribution of X-ray-selected AGNs
Georgakakis, A.; Salvato, M.; Schulze, A. +5 more
This paper estimates the specific accretion-rate distribution of AGNs using a sample of 4821 X-ray sources from both deep and shallow surveys. The specific accretion-rate distribution is used as a proxy of the Eddington ratio and is defined as the probability of a galaxy with a given stellar mass and redshift hosting an active nucleus with a certa…
The earliest phases of high-mass star formation, as seen in NGC 6334 by Herschel-HOBYS
Bernard, J. -P.; Martin, P. G.; Hill, T. +33 more
Aims: To constrain models of high-mass star formation, the Herschel-HOBYS key program aims at discovering massive dense cores (MDCs) able to host the high-mass analogs of low-mass prestellar cores, which have been searched for over the past decade. We here focus on NGC 6334, one of the best-studied HOBYS molecular cloud complexes.
Method…
The Extent of Chemically Enriched Gas around Star-forming Dwarf Galaxies
Johnson, Sean D.; Chen, Hsiao-Wen; Mulchaey, John S. +2 more
Supernova driven winds are often invoked to remove chemically enriched gas from dwarf galaxies to match their low observed metallicities. In such shallow potential wells, outflows may produce massive amounts of enriched halo gas (circumgalactic medium, CGM) and pollute the intergalactic medium (IGM). Here, we present a survey of the CGM and IGM ar…
Turbulent Kinetic Energy in the Energy Balance of a Solar Flare
Harra, L. K.; Kontar, E. P.; Perez, J. E. +5 more
The energy released in solar flares derives from a reconfiguration of magnetic fields to a lower energy state, and is manifested in several forms, including bulk kinetic energy of the coronal mass ejection, acceleration of electrons and ions, and enhanced thermal energy that is ultimately radiated away across the electromagnetic spectrum from opti…