Search Publications
Modeling protoplanetary disk SEDs with artificial neural networks. Revisiting the viscous disk model and updated disk masses
Sarro, L. M.; Ribas, Á.; Macías, E. +1 more
We model the spectral energy distributions (SEDs) of 23 protoplanetary disks in the Taurus-Auriga star-forming region using detailed disk models and a Bayesian approach. This is made possible by combining these models with artificial neural networks to drastically speed up their performance. Such a setup allows us to confront α-disk models with ob…
Observation of the Second LIGO/Virgo Event Connected with a Binary Neutron Star Merger S190425z in the Gamma-Ray Range
Minaev, P. Yu.; Pozanenko, A. S.; Grebenev, S. A. +1 more
The results of observations of the gravitational-wave (GW) event S190425z recorded by the LIGO/Virgo detectors with the anti-coincidence shield (ACS) of the SPI gamma-ray spectrometer onboard the INTEGRAL observatory are presented. With a high probability (>99%) it was associated with a neutron star (NS) merger in a close binary system. This is…
Demographics of disks around young very low-mass stars and brown dwarfs in Lupus
de Gregorio-Monsalvo, I.; Henning, T.; Pascucci, I. +15 more
We present new 890 µm continuum ALMA observations of five brown dwarfs (BDs) with infrared excess in Lupus I and III, which in combination with four previously observed BDs allowed us to study the millimeter properties of the full known BD disk population of one star-forming region. Emission is detected in five out of the nine BD disks. Dust…
Size and Shape Constraints of (486958) Arrokoth from Stellar Occultations
Dunham, David W.; Tanga, Paolo; Singer, Kelsi N. +130 more
We present the results from four stellar occultations by (486958) Arrokoth, the flyby target of the New Horizons extended mission. Three of the four efforts led to positive detections of the body, and all constrained the presence of rings and other debris, finding none. Twenty-five mobile stations were deployed for 2017 June 3 and augmented by fix…
Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap?
Fridlund, M.; Rauer, H.; Amado, P. J. +81 more
We report the confirmation of a transiting planet around the bright weakly active M0.5 V star TOI-1235 (TYC 4384-1735-1, V ≈ 11.5 mag), whose transit signal was detected in the photometric time series of sectors 14, 20, and 21 of the TESS space mission. We confirm the planetary nature of the transit signal, which has a period of 3.44 d, by using p…
Magnetic Field Dependence of Bipolar Magnetic Region Tilts on the Sun: Indication of Tilt Quenching
Banerjee, Dipankar; Jha, Bibhuti Kumar; Karak, Bidya Binay +1 more
The tilt of the bipolar magnetic region (BMR) is crucial in the Babcock-Leighton process for the generation of the poloidal magnetic field in the Sun. Based on the thin flux-tube model of the BMR formation, the tilt is believed to be caused by the Coriolis force acting on the rising flux tube of the strong toroidal magnetic field from the base of …
Climatology of SO2 and UV absorber at Venus' cloud top from SPICAV-UV nadir dataset
Montmessin, Franck; Bertaux, Jean-Loup; Korablev, Oleg +6 more
Following our previous work (Marcq et al., 2013, 2011), we have updated our forward radiative transfer code and processed the whole SPICAV-UV/Venus Express nadir dataset (2006-2014) in order to retrieve SO2 abundance at cloud top - assuming a SO2 decreasing scale height of 3 km and a ratio SO/SO2 tied to 10% - as w…
An ultra-massive white dwarf with a mixed hydrogen-carbon atmosphere as a likely merger remnant
Gänsicke, B. T.; Dhillon, V. S.; Tremblay, P. -E. +11 more
White dwarfs are dense, cooling stellar embers consisting mostly of carbon and oxygen1, or oxygen and neon (with a few per cent carbon) at higher initial stellar masses2. These stellar cores are enveloped by a shell of helium, which in turn, is usually surrounded by a layer of hydrogen, generally prohibiting direct observatio…
Asteroseismology of luminous red giants with Kepler I: long-period variables with radial and non-radial modes
Huber, Daniel; Bedding, Timothy R.; Stello, Dennis +4 more
While long-period variables (LPVs) have been extensively investigated, especially with MACHO and OGLE data for the Magellanic Clouds, there still exist open questions in their pulsations regarding the excitation mechanisms, radial order, and angular degree assignment. Here, we perform asteroseismic analyses on LPVs observed by the 4-year Kepler mi…
The little things matter: relating the abundance of ultrafaint satellites to the hosts' assembly history
Belokurov, Vasily; Deason, Alis J.; Bose, Sownak +1 more
Ultrafaint dwarf galaxies ( $M_\star \le 10^{5}\, {\rm M}_\odot$ ) are relics of an early phase of galaxy formation. They contain some of the oldest and most metal-poor stars in the Universe which likely formed before the epoch of hydrogen reionization. These galaxies are so faint that they can only be detected as satellites of the Milky Way. They…