Search Publications
Binarity among CEMP-no stars: an indication of multiple formation pathways?
Arentsen, A.; Starkenburg, E.; Venn, K. A. +3 more
Carbon-enhanced metal-poor (CEMP) stars comprise a high percentage of stars at the lowest metallicities. The stars in the CEMP-no subcategory do not show any s-process enhancement and therefore cannot easily be explained by transfer of carbon and s-process elements from a binary AGB companion. We have performed radial velocity monitoring of a samp…
A contribution of star-forming clumps and accreting satellites to the mass assembly of z ∼ 2 galaxies
Daddi, E.; Le Floc'h, E.; Bournaud, F. +14 more
We investigate the contribution of clumps and satellites to the galaxy mass assembly. We analysed spatially resolved HubbleSpace Telescope observations (imaging and slitless spectroscopy) of 53 star-forming galaxies at z ∼ 1-3. We created continuum and emission line maps and pinpointed residual `blobs' detected after subtracting the galaxy disc. T…
Early- and late-stage mergers among main sequence and starburst galaxies at 0.2 ≤ z ≤ 2
Daddi, E.; Elbaz, D.; Le Floc'h, E. +12 more
We investigate the fraction of close pairs and morphologically identified mergers on and above the star-forming main sequence (MS) at 0.2 ≤ z ≤2.0. The novelty of our work lies in the use of a non-parametric morphological classification performed on resolved stellar mass maps, reducing the contamination by non-interacting, high-redshift clumpy gal…
A volume-limited survey of mCP stars within 100 pc - I. Fundamental parameters and chemical abundances
Wade, G. A.; Neiner, C.; Sikora, J. +1 more
We present the first results of a volume-limited survey of main-sequence (MS) magnetic chemically peculiar (mCP) stars. The sample consists of all identified intermediate-mass MS stars (mCP and non-mCP) within a heliocentric distance of 100 pc as determined using Hipparcos parallaxes. The two populations are compared in order to determine the uniq…
Exploring the Age-dependent Properties of M and L Dwarfs Using Gaia and SDSS
Angus, Ruth; Kiman, Rocio; Faherty, Jacqueline K. +3 more
We present a sample of 74,216 M and L dwarfs constructed from two existing catalogs of cool dwarfs spectroscopically identified in the Sloan Digital Sky Survey (SDSS). We cross-matched the SDSS catalog with Gaia DR2 to obtain parallaxes and proper motions and modified the quality cuts suggested by the Gaia Collaboration to make them suitable for l…
Radial velocity confirmation of K2-100b: a young, highly irradiated, and low-density transiting hot Neptune
Tamura, M.; Aigrain, S.; Pagano, I. +37 more
We present a detailed analysis of HARPS-N radial velocity observations of K2-100, a young and active star in the Praesepe cluster, which hosts a transiting planet with a period of 1.7 d. We model the activity-induced radial velocity variations of the host star with a multidimensional Gaussian Process framework and detect a planetary signal of 10.6…
Characterization of the L 98-59 multi-planetary system with HARPS. Mass characterization of a hot super-Earth, a sub-Neptune, and a mass upper limit on the third planet
Bouchy, F.; Doyon, R.; Ségransan, D. +33 more
Aims: L 98-59 (TIC 307210830, TOI-175) is a nearby M3 dwarf around which TESS revealed three small transiting planets (0.80, 1.35, 1.57 Earth radii) in a compact configuration with orbital periods shorter than 7.5 days. Here we aim to measure the masses of the known transiting planets in this system using precise radial velocity (RV) measurem…
Hard X-ray view on intermediate polars in the Gaia era
Doroshenko, Victor; Suleimanov, Valery F.; Werner, Klaus
The hardness of the X-ray spectra of intermediate polars (IPs) is determined mainly by the white dwarf (WD) compactness (mass-radius ratio, M/R) and, thus, hard X-ray spectra can be used to constrain the WD mass. An accurate mass estimate requires the finite size of the WD magnetosphere Rm to be taken into the account. We suggested to d…
Pulsating in Unison at Optical and X-Ray Energies: Simultaneous High Time Resolution Observations of the Transitional Millisecond Pulsar PSR J1023+0038
Campana, S.; Stella, L.; Sanna, A. +22 more
PSR J1023+0038 is the first millisecond pulsar discovered to pulsate in the visible band; such a detection took place when the pulsar was surrounded by an accretion disk and also showed X-ray pulsations. We report on the first high time resolution observational campaign of this transitional pulsar in the disk state, using simultaneous observations…
Reconciling mass estimates of ultradiffuse galaxies
Laporte, Chervin F. P.; Navarro, Julio F.; Agnello, Adriano
The virial masses of ultradiffuse galaxies (UDGs) have been estimated using the kinematics and abundance of their globular cluster populations, leading to disparate results. Some studies conclude that UDGs reside in massive dark matter haloes while van Dokkum et al., controversially, argue for the existence of UDGs with no dark matter at all. Here…