Search Publications
Chandra and ALMA observations of the nuclear activity in two strongly lensed star-forming galaxies
Danese, L.; Massardi, M.; Enia, A. F. M. +7 more
Aim. According to coevolutionary scenarios, nuclear activity and star formation play relevant roles in the early stages of galaxy formation. We aim at identifying them in high-redshift galaxies by exploiting high-resolution and high-sensitivity X-ray and millimeter-wavelength data to confirm the presence or absence of star formation and nuclear ac…
Absolute Properties of the Pulsating Post-mass Transfer Eclipsing Binary OO Draconis
Koo, Jae-Rim; Hong, Kyeongsoo; Lee, Jae Woo +1 more
OO Dra is a short-period Algol system with a δ Sct-like pulsator. We obtained time-series spectra between 2016 February and May to derive the fundamental parameters of the binary star and to study its evolutionary scenario. The radial velocity (RV) curves for both components were presented, and the effective temperature of the hotter and more mass…
Updated astrometry and masses of the LUH 16 brown dwarf binary
Sahlmann, J.; Lazorenko, P. F.
The nearest known binary brown dwarf WISE J104915.57-531906.1AB (LUH 16) is a well-studied benchmark for our understanding of substellar objects. Previously published astrometry of LUH 16 obtained with FORS2 on the Very Large Telescope was affected by errors that limited its use in combination with other datasets, thereby hampering the determinati…
Global hot-star wind models for stars from Magellanic Clouds
Krtička, J.; Kubát, J.
We provide mass-loss rate predictions for O stars from Large and Small Magellanic Clouds. We calculate global (unified, hydrodynamic) model atmospheres of main sequence, giant, and supergiant stars for chemical composition corresponding to Magellanic Clouds. The models solve radiative transfer equation in comoving frame, kinetic equilibrium equati…
Star Formation Histories of the LEGUS Dwarf Galaxies. II. Spatially Resolved Star Formation History of the Magellanic Irregular NGC 4449
Cignoni, M.; Tosi, M.; Sabbi, E. +16 more
We present a detailed study of the Magellanic irregular galaxy NGC 4449 based on both archival and new photometric data from the Legacy Extragalactic UV Survey, obtained with the Hubble Space Telescope Advanced Camera for Surveys and Wide Field Camera 3. Thanks to its proximity (D = 3.82 ± 0.27 Mpc), we reach stars 3 mag fainter than the tip of th…
Onset of Photospheric Impacts and Helioseismic Waves in X9.3 Solar Flare of 2017 September 6
Kosovichev, Alexander G.; Sharykin, Ivan N.
The X9.3 flare of 2017 September 6, was the most powerful flare of Solar Cycle 24. It generated strong white-light emission and multiple helioseismic waves (sunquakes). By using data from the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory as well as hard X-ray (HXR) data from the KONUS instrument on board the WIND s…
"TNOs are Cool": A survey of the trans-Neptunian region. XIV. Size/albedo characterization of the Haumea family observed with Herschel and Spitzer
Fornasier, S.; Pál, A.; Lellouch, E. +14 more
Context. A group of trans-Neptunian objects (TNOs) are dynamically related to the dwarf planet 136108 Haumea. Ten of them show strong indications of water ice on their surfaces, are assumed to have resulted from a collision, and are accepted as the only known TNO collisional family. Nineteen other dynamically similar objects lack water ice absorpt…
The COS-AGN survey: revealing the nature of circumgalactic gas around hosts of active galactic nuclei
Ellison, Sara L.; Tumlinson, Jason; Schaye, Joop +4 more
Active galactic nuclei (AGN) are thought to play a critical role in shaping galaxies, but their effect on the circumgalactic medium (CGM) is not well studied. We present results from the COS-AGN survey: 19 quasar sightlines that probe the CGM of 20 optically selected AGN host galaxies with impact parameters 80<ρimp<300 kpc. Absorp…
A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA
Smith, Nathan; Ginsburg, Adam; Bally, John
We present Atacama Large Millimeter Array (ALMA) observations of 12CO 2-1 emission from circumstellar material around the massive star Eta Carinae (η Car). These observations reveal new structural details about the cool equatorial torus located ∼4000 au from the star. The CO torus is not a complete azimuthal loop, but rather, is missing…
The dusty aftermath of SN Hunt 248: merger-burst remnant?
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Fox, Ori D. +3 more
SN Hunt 248 was classified as a non-terminal eruption (a supernova 'impostor') from a directly identified and highly variable cool hypergiant star. The 2014 outburst achieved peak luminosity equivalent to that of the historic eruption of luminous blue variable (LBV) η Car, and exhibited a multipeaked optical light curve which rapidly faded after ∼…