Search Publications
The non-explosive stellar merging origin of the ultra-massive carbon-rich white dwarfs
Vennes, Stéphane; Ferrario, Lilia; Kawka, Adela
We have investigated the origin of a sub-class of carbon-polluted white dwarfs (DQ) originally identified as the "hot DQ" white dwarfs. These objects are relatively hot ($10\, 000\lesssim T_{\rm eff}\lesssim 25\, 000$ K), have markedly higher carbon abundance (C-enriched), are more massive (M ≳ 0.8 M⊙) than ordinary DQs (M ~ 0.6 M⊙…
Evidence for extended gaseous reservoirs around AGN at cosmic noon from ALMA CO(3-2) observations
Maiolino, R.; Fudamoto, Y.; Carniani, S. +3 more
Gaseous outflows are key phenomena in the evolution of galaxies, as they affect star formation (either positively or negatively), eject gas from the core or disc, and directly cause mixing of pristine and processed material. Active outflows may be detected through searches for broad spectral line emission or high-velocity gas, but it is also possi…
Testing super-eddington accretion on to a supermassive black hole: reverberation mapping of PG 1119+120
Ho, Luis C.; Horne, Keith; Du, Pu +11 more
We measure the black hole mass and investigate the accretion flow around the local (z = 0.0502) quasar PG 1119+120. Spectroscopic monitoring with Calar Alto provides H β lags and linewidths from which we estimate a black hole mass of log (M•/M⊙) = 7.0, uncertain by ~0.4 dex. High cadence photometric monitoring over 2 yr with …
Late-time HST UV and optical observations of AT 2018cow: extracting a cow from its background
Jonker, Peter G.; Perley, Daniel A.; Mummery, Andrew +4 more
The bright, blue, rapidly evolving AT 2018cow is a well-studied peculiar extragalactic transient. Despite an abundance of multiwavelength data, there still is no consensus on the nature of the event. We present our analysis of three epochs of Hubble Space Telescope (HST) observations spanning the period from 713 to 1474 d post-burst, paying partic…
Volatiles in the H2O and CO2 ices of comet 67P/Churyumov-Gerasimenko
De Keyser, Johan; Gombosi, Tamas I.; Berthelier, Jean-Jacques +11 more
European Space Agency's Rosetta spacecraft at comet 67P/Churyumov-Gerasimenko (67P) was the first mission that accompanied a comet over a substantial fraction of its orbit. On board was the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis mass spectrometer suite to measure the local densities of the volatile species sublimating from the i…
The oblateness of the Milky Way dark matter halo from the stellar streams of NGC 3201, M68, and Palomar 5
Miralda-Escudé, Jordi; Palau, Carles G.
We explore constraints on the Milky Way dark matter halo oblateness using three stellar streams from globular clusters NGC3201, M68, and Palomar 5. Previous constraints on the gravitational potential from dynamical equilibrium of stellar populations and distant Milky Way satellites are included. We model the dark halo as axisymmetric with axis rat…
Radio AGN selection and characterization in three Deep-Drilling Fields of the Vera C. Rubin Observatory Legacy Survey of Space and Time
Brandt, W. N.; Zou, Fan; Luo, Bin +4 more
The Australia Telescope Large Area Survey (ATLAS) and the VLA survey in the XMM-LSS/VIDEO deep field provide deep (≈15 $\mu$ Jy beam-1) and high-resolution (≈4.5-8 arcsec) radio coverage of the three XMM-SERVS fields (W-CDF-S, ELAIS-S1, and XMM-LSS). These data cover a total sky area of 11.3 deg2 and contain ≈11 000 radio com…
The Calar Alto Legacy Integral Field Area survey: extended and remastered data release
Galbany, L.; Walcher, C. J.; Sánchez, S. F. +2 more
This paper describes the extended data release (eDR) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. It comprises science-grade quality data for 895 galaxies obtained with the Potsdam Multi Aperture Spectograph/PPak instrument at the 3.5-m telescope at the Calar Alto Observatory along the last 12 yr, using the V500 setup [3700-7500 Å…
Swing amplification and the Gaia phase spirals
Widrow, Lawrence M.
We explore the interplay between in-plane and vertical dynamics in stellar discs within the framework of the shearing box approximation. Julian and Toomre used the shearing sheet to show that leading density waves are amplified as they swing into trailing ones. We extend their formalism into the dimension perpendicular to the disc to obtain explic…
Surveying nearby brown dwarfs with HGCA: direct imaging discovery of a faint, high-mass brown dwarf orbiting HD 176535 A
Jensen-Clem, Rebecca; Currie, Thayne; Lewis, Briley L. +17 more
Brown dwarfs with well-measured masses, ages, and luminosities provide direct benchmark tests of substellar formation and evolutionary models. We report the first results from a direct imaging survey aiming to find and characterize substellar companions to nearby accelerating stars with the assistance of the Hipparcos-Gaia Catalog of Accelerations…