Search Publications
Missions
Journals
Publication Years
A Near-infrared Look at AGN Feedback in Bulgeless Galaxies
Bohn, Thomas; Canalizo, Gabriela; Satyapal, Shobita +1 more
While it is generally believed that supermassive black holes (SMBHs) lie in most galaxies with bulges, few SMBHs have been confirmed in bulgeless galaxies. Identifying such a population could provide important insights to the BH seed population and secular BH growth. To this end, we obtained near-infrared (NIR) spectroscopic observations of a samp…
Linking high- and low-mass star formation. Observation-based continuum modelling and physical conditions
Kristensen, L. E.; Jørgensen, J. K.; Pitts, R. L. +1 more
Context. Astronomers have yet to establish whether high-mass protostars form from high-mass prestellar cores, similar to their lower-mass counterparts, or from lower-mass fragments at the heart of a pre-protostellar cluster undergoing large-scale collapse. Part of the uncertainty is due to a shortage of envelope structure data on protostars of a f…
Changes in the Na D1 Absorption Components of η Carinae Provide Clues on the Location of the Dissipating Central Occulter
Moffat, Anthony F. J.; Hillier, D. John; Gull, Theodore R. +9 more
The Na D absorption doublet in the spectrum of η Carinae is complex, with multiple absorption features associated with the Great Eruption (1840s), the Lesser Eruption (1890s), and the interstellar clouds. The velocity profile is further complicated by the P Cygni profile originating in the system's stellar winds and blending with the He I λ5876 pr…
Broad-line region clouds orbiting an AGN sample
Logan, C. H. A.; Llerena, M.; Armijos-Abendaño, J. +1 more
We present a spectral and temporal analysis of XMM-Newton data from a sample of six galaxies (NGC 3783, Mrk 279, Mrk 766, NGC 3227, NGC 7314, and NGC 3516). Using the hardness-ratio curves, we identify time intervals in which clouds are eclipsing the central X-ray source in five of the six sources. We detect three occultations in NGC 3227 and one …
Radial profiles of lensed z ∼ 1 galaxies on sub-kiloparsec scales
Richard, Johan; Chisholm, John; Schaerer, Daniel +4 more
We study the spatially resolved physical properties of the Cosmic Snake arc in MACS J1206.2-0847 and the arc in Abell 0521 (A521). These are two strongly lensed galaxies at redshifts z = 1.036 and z = 1.044. We used observations of the Hubble Space Telescope (HST) and the Atacama Large Millimeter/submillimeter Array (ALMA). The former gives access…
Kinematics of the Central Stars Powering Bowshock Nebulae and the Large Multiplicity Fraction of Runaway OB Stars
Kobulnicky, Henry A.; Chick, William T.
OB stars powering stellar bowshock nebulae (SBNe) have been presumed to have large peculiar velocities. We measured peculiar velocities of SBN central stars to assess their kinematics relative to the general O-star population using Gaia EDR3 data for 267 SBN central stars and a sample of 455 Galactic O stars to derive projected velocities v 2…
Probing modified Newtonian dynamics with hypervelocity stars
Gallo, Arianna; Ostorero, Luisa; Chakrabarty, Sankha Subhra +2 more
We show that measuring the velocity components of hypervelocity stars (HVSs) can discriminate between modified Newtonian dynamics (MOND) and Newtonian gravity. Hypervelocity stars are ejected from the Galactic center on radial trajectories with a null tangential velocity component in the reference frame of the Galaxy. They acquire tangential compo…
Tomography of the environment of the COSMOS/AzTEC-3 submillimeter galaxy at z ∼ 5.3 revealed by Lyα and MUSE observations
Dannerbauer, H.; Marino, R.; da Cunha, E. +8 more
Context. Submillimeter galaxies (SMGs) have been proposed as the progenitors of massive ellipticals in the local Universe. Mapping the neutral gas distribution and investigating the gas accretion toward the SMGs at high redshift can provide information on the way SMG environments can evolve into clusters at z = 0.
Aims: In this work, we study…
A Review of the Extended EUV Corona Observed by the Sun Watcher with Active Pixels and Image Processing (SWAP) Instrument
Berghmans, David; West, Matthew J.; Mierla, Marilena +7 more
The Sun Watcher with Active Pixels and Image Processing (SWAP) instrument onboard ESA's PRoject for On Board Autonomy 2 (PROBA2) has provided the first uncompressed, high-cadence, continuous, large field-of-view observations of the extended extreme-ultraviolet (EUV) corona for over a complete solar cycle. It has helped shape our understanding of t…
Identifying the 3FHL Catalog. VI. Swift Observations of 3FHL Unassociated Objects with Source Classification via Machine Learning
Ajello, M.; Marchesi, S.; Torres-Albà, N. +5 more
The Third Catalog of Hard Fermi Large Area Telescope Sources (3FHL) reports the detection of 1556 objects at E > 10 GeV. However, 177 sources remain unassociated and 23 are associated with a ROSAT X-ray detection of unknown origin. Pointed X-ray observations were conducted on 30 of these unassociated and unknown sources with Swift-XRT. A bright…