Search Publications
VINTERGATAN - I. The origins of chemically, kinematically, and structurally distinct discs in a simulated Milky Way-mass galaxy
Feuillet, Diane K.; Feltzing, Sofia; Ryde, Nils +6 more
Spectroscopic surveys of the Milky Way's stars have revealed spatial, chemical, and kinematical structures that encode its history. In this work, we study their origins using a cosmological zoom simulation, VINTERGATAN, of a Milky Way-mass disc galaxy. We find that in connection to the last major merger at z ∼ 1.5, cosmological accretion leads to …
A unicorn in monoceros: the 3 M⊙ dark companion to the bright, nearby red giant V723 Mon is a non-interacting, mass-gap black hole candidate
Strassmeier, K. G.; Weber, M.; Ilyin, I. +18 more
We report the discovery of the closest known black hole candidate as a binary companion to V723 Mon. V723 Mon is a nearby ($d\sim 460\, \rm pc$), bright (V ≃ 8.3 mag), evolved (Teff, giant ≃ 4440 K, and Lgiant ≃ 173 L⊙) red giant in a high mass function, f(M) = 1.72 ± 0.01 M⊙, nearly circular binary (P =…
Discovery and follow-up of ASASSN-19dj: an X-ray and UV luminous TDE in an extreme post-starburst galaxy
Kochanek, C. S.; Foley, R. J.; Stalder, B. +28 more
We present observations of ASASSN-19dj, a nearby tidal disruption event (TDE) discovered in the post-starburst galaxy KUG 0810+227 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d ≃ 98 Mpc. We observed ASASSN-19dj from -21 to 392 d relative to peak ultraviolet (UV)/optical emission using high-cadence, multiwavelength spe…
HELP: the Herschel Extragalactic Legacy Project
Aussel, H.; Shirley, R.; Buat, V. +29 more
We present the Herschel Extragalactic Legacy Project (HELP). This project collates, curates, homogenizes, and creates derived data products for most of the premium multiwavelength extragalactic data sets. The sky boundaries for the first data release cover 1270 deg2 defined by the Herschel SPIRE extragalactic survey fields; notably the …
A self-lensing binary massive black hole interpretation of quasi-periodic eruptions
Ingram, Adam; Aigrain, Suzanne; Motta, Sara E. +1 more
Binary supermassive black hole (SMBH) systems result from galaxy mergers, and will eventually coalesce due to gravitational wave (GW) emission if the binary separation can be reduced to ≲0.1 pc by other mechanisms. Here, we explore a gravitational self-lensing binary SMBH model for the sharp (duration ~1 h), quasi-regular X-ray flares - dubbed qua…
A hard X-ray view of luminous and ultra-luminous infrared galaxies in GOALS - I. AGN obscuration along the merger sequence
Sanders, D. B.; Stern, D.; Inami, H. +25 more
The merger of two or more galaxies can enhance the inflow of material from galactic scales into the close environments of active galactic nuclei (AGNs), obscuring and feeding the supermassive black hole (SMBH). Both recent simulations and observations of AGN in mergers have confirmed that mergers are related to strong nuclear obscuration. However,…
Measuring fundamental jet properties with multiwavelength fast timing of the black hole X-ray binary MAXI J1820+070
Maccarone, T. J.; Dhillon, V. S.; Gandhi, P. +9 more
We present multiwavelength fast timing observations of the black hole X-ray binary MAXI J1820+070 (ASASSN-18ey), taken with the Karl G. Jansky Very Large Array (VLA), Atacama Large Millimeter/Sub-Millimeter Array (ALMA), Very Large Telescope (VLT), New Technology Telescope (NTT), Neutron Star Interior Composition Explorer (NICER), and XMM-Newton. …
Einstein@Home discovery of the gamma-ray millisecond pulsar PSR J2039-5617 confirms its predicted redback nature
Dhillon, V. S.; Guillemot, L.; Harding, A. K. +19 more
The Fermi Large Area Telescope gamma-ray source 3FGL J2039.6-5618 contains a periodic optical and X-ray source that was predicted to be a 'redback' millisecond pulsar (MSP) binary system. However, the conclusive identification required the detection of pulsations from the putative MSP. To better constrain the orbital parameters for a directed sear…
The UV-brightest Lyman continuum emitting star-forming galaxy
Pérez-Fournon, I.; Schaerer, D.; Marques-Chaves, R. +5 more
We report the discovery of J0121+0025, an extremely luminous and young star-forming galaxy (MUV = -24.11, log[$L_{\rm Ly \alpha } / \rm erg~s^{-1}] = 43.8$) at z = 3.244 showing copious Lyman continuum (LyC) leakage ($f_{\rm esc, abs} \approx 40{{\ \rm per\ cent}}$). High signal-to-noise ratio rest-frame UV spectroscopy with the Gran Te…
XMM-Newton campaign on the ultraluminous X-ray source NGC 247 ULX-1: outflows
Fabian, A. C.; Pinto, C.; D'Aì, A. +13 more
Most ultraluminous X-ray sources (ULXs) are believed to be powered by super-Eddington accreting neutron stars and, perhaps, black holes. Above the Eddington rate the disc is expected to thicken and to launch powerful winds through radiation pressure. Winds have been recently discovered in several ULXs. However, it is yet unclear whether the thicke…