Search Publications
Uncovering a hidden black hole binary from secular eccentricity variations of a tertiary star
Liu, Bin; D'Orazio, Daniel J.; Vigna-Gómez, Alejandro +1 more
We study the dynamics of a solar-type star orbiting around a black hole binary (BHB) in a nearly coplanar system. We present a novel effect that can prompt a growth and significant oscillations of the eccentricity of the stellar orbit when the system encounters an "apsidal precession resonance," where the apsidal precession rate of the outer stell…
CORALIE radial-velocity search for companions around evolved stars (CASCADES). I. Sample definition and first results: Three new planets orbiting giant stars
Buldgen, G.; Eggenberger, P.; Ségransan, D. +11 more
Context. Following the first discovery of a planet orbiting a giant star in 2002, we started the CORALIE radial-velocity search for companions around evolved stars. We present the observations of three stars conducted at the 1.2 m Leonard Euler Swiss telescope at La Silla Observatory, Chile, using the CORALIE spectrograph.
Aims: We aim to det…
The Mg-K Anticorrelation in ω Centauri
Mucciarelli, Alessio; Bellazzini, Michele; Lardo, Carmela +2 more
We present [K/Fe] abundance ratios for a sample of 450 stars in ω Centauri, using high-resolution spectra acquired with the multiobject spectrograph FLAMES@VLT. Abundances for Fe, Na, and Mg were also derived. We detected intrinsic K variations in the analyzed stars. Moreover, [K/Fe] shows a significant correlation with [Na/Fe] and an anticorrelat…
Formation of Sources for Solar Cosmic Rays in Eruptive Flares X6.9 and M5.1 Observed August 9, 2011, and May 17, 2012
Struminsky, A. B.; Grigorieva, I. Yu.
A coronal mass ejection (CME) and solar proton event (SPE) succeeding weak flares in soft X-rays and being observed in the interplanetary space (IS) is not any unusual. However, it remains unclear in what way extreme CME and SPE characteristics can be realized in such cases. The present work compares solar and IS observations associated with the l…
Evidence for Centrifugal Breakout around the Young M Dwarf TIC 234284556
Montet, Benjamin T.; Hartman, Joel D.; Feinstein, Adina D. +5 more
Magnetospheric clouds have been proposed as explanations for depth-varying dips in the phased light curves of young, magnetically active stars such as σ Ori E and RIK-210. However, the stellar theory that first predicted magnetospheric clouds also anticipated an associated mass-balancing mechanism known as centrifugal breakout for which there has …
The star formation rates of QSOs
Andreani, P.; Ivison, R. J.; Clements, D. L. +13 more
We examine the far-infrared (FIR) properties of a sample of 5391 optically selected QSOs in the 0.5 < z < 2.65 redshift range down to log [νLν, 2500(erg s-1)] > 44.7, using SPIRE data from Herschel-ATLAS. We split the sample in a grid of 74 luminosity-redshift bins and compute the average optical-IR spectral energy d…
A giant planet shaping the disk around the very low-mass star CIDA 1
Lodato, G.; Testi, L.; Lombardi, M. +13 more
Context. Exoplanetary research has provided us with exciting discoveries of planets around very low-mass (VLM) stars (0.08 M⊙ ≲ M* ≲ 0.3 M⊙; e.g., TRAPPIST-1 and Proxima Centauri). However, current theoretical models still strive to explain planet formation in these conditions and do not predict the development of …
High resolution X-ray spectroscopy of V4641 Sgr during its 2020 outburst
Heinke, C. O.; Miller, J. M.; Gandhi, P. +7 more
We observed the Galactic black hole X-ray binary V4641 Sgr with the high resolution transmission gratings on Chandra during the source's 2020 outburst. Over two epochs of Chandra gratings observations, we see numerous highly ionized metal lines, superimposed on a hot, disc-dominated X-ray continuum. The measured inner disc temperatures and luminos…
SHARP - VIII. J0924+0219 lens mass distribution and time-delay prediction through adaptive-optics imaging
Treu, Tommaso; Lagattuta, David J.; Fassnacht, Christopher D. +6 more
Strongly lensed quasars can provide measurements of the Hubble constant (H0) independent of any other methods. One of the key ingredients is exquisite high-resolution imaging data, such as Hubble Space Telescope (HST) imaging and adaptive-optics (AO) imaging from ground-based telescopes, which provide strong constraints on the mass dist…
The Internal Proper Motion Kinematics of NGC 346: Past Formation and Future Evolution
Anderson, J.; Lennon, D. J.; Sabbi, E. +6 more
We investigate the internal kinematics of the young star-forming region NGC 346 in the Small Magellanic Cloud (SMC). We used two epochs of deep F555W and F814W Hubble Space Telescope Advanced Camera for Surveys observations with an 11 yr baseline to determine proper motions and study the kinematics of different populations, as identified by their …