Search Publications
Improving White Dwarfs as Chronometers with Gaia Parallaxes and Spectroscopic Metallicities
Fouesneau, Morgan; El-Badry, Kareem; Bailer-Jones, Coryn A. L. +9 more
White dwarfs (WDs) offer unrealized potential in solving two problems in astrophysics: stellar age accuracy and precision. WD cooling ages can be inferred from surface temperatures and radii, which can be constrained with precision by high-quality photometry and parallaxes. Accurate and precise Gaia parallaxes along with photometric surveys provid…
Parameters of the Radcliffe Wave from Masers, Radio Stars, and T Tauri Stars
Bobylev, V. V.; Bajkova, A. T.; Mishurov, Yu. N.
The Radcliffe wave is shown to be present in both positions and vertical velocities of masers and radio stars belonging to the Local Arm. At the same time, it appears that the Radcliffe structure is not a wave in the true sense of the word. It more closely resembles a local high-amplitude spike that rapidly tails off. This structure has the larges…
On the use of field RR Lyrae as galactic probes - VI. Mixed mode RR Lyrae variables in Fornax and in nearby dwarf galaxies
Di Criscienzo, M.; Marinoni, S.; Marrese, P. M. +11 more
We investigate the properties of the mixed-mode (RRd) RR Lyrae (RRL) variables in the Fornax dwarf spheroidal (dSph) galaxy by using B- and V-band time series collected over 24 yr. We compare the properties of the RRds in Fornax with those in the Magellanic Clouds and in nearby dSphs, with special focus on Sculptor. We found that the ratio of RRds…
Vertical distribution of dust in the Martian atmosphere: OMEGA/MEx limb observations
Aoki, Shohei; Bellucci, Giancarlo; Altieri, Francesca +8 more
The OMEGA spectrometer on board Mars Express acquired several observations of the Martian limb that are still largely unexploited. Here, we explore the information content of these data in terms of abundance and size of the Martian atmospheric dust. We approach the dust retrievals by applying a full spherical multiple scattering Monte Carlo 1D rad…
Spectral-timing of AGN ionized outflows with Athena
Costantini, E.; Uttley, P.; Juráňová, A.
Spectral-timing techniques have proven valuable in studying the interplay between the X-ray corona and the accretion disc in variable active galactic nuclei (AGNs). Under certain conditions, photoionized outflows emerging from central AGN regions also play a role in the observable spectral-timing properties of the nuclear components. The variable …
Helium line emissivities for nebular astrophysics
Del Zanna, G.; Storey, P. J.
We present the results of several collisional-radiative models describing optically thin emissivities of the main lines in neutral helium formed by recombination, for a grid of electron temperatures and densities, typical of H II regions and planetary nebulae. Accurate emissivities are required for example to measure the helium abundance in nebula…
Compton-thick AGN in the NuSTAR Era. IX. A Joint NuSTAR and XMM-Newton Analysis of Four Local AGN
Cusumano, G.; Ajello, M.; La Parola, V. +7 more
We present the results of the broadband X-ray spectral analysis of simultaneous NuSTAR and XMM-Newton observations of four nearby Compton-thick active galactic nuclei (AGN) candidates selected from the Swift Burst Alert Telescope 150 month catalog. This work is part of a larger effort to identify and characterize all Compton-thick (N H …
Tracers of Dense Gas in the Outer Galaxy
Jose, Jessy; Kim, Kee-Tae; Kauffmann, Jens +5 more
We have mapped $\mathrm{HCN}$ and HCO+ (J = 1 → 0) line emission toward a sample of seven star-forming regions (with $12+\mathrm{log}[{\rm{O}}/{\rm{H}}]$ ranging from 8.34 to 8.69) in the outer Milky Way (Galactocentric distance >9.5 kpc), using the 14 m radio telescope of the Taeduk Radio Astronomy Observatory. We compare these two …
Transit timings variations in the three-planet system: TOI-270
Gorjian, Varoujan; Mikal-Evans, Thomas; Triaud, Amaury H. M. J. +69 more
We present ground- and space-based photometric observations of TOI-270 (L231-32), a system of three transiting planets consisting of one super-Earth and two sub-Neptunes discovered by TESS around a bright (K-mag = 8.25) M3V dwarf. The planets orbit near low-order mean-motion resonances (5:3 and 2:1) and are thus expected to exhibit large transit t…
One Star to Tag Them All (OSTTA). I. Radial velocities and chemical abundances for 20 poorly studied open clusters
Baratella, M.; Jordi, C.; Casamiquela, L. +9 more
Context. Open clusters are ideal laboratories to investigate a variety of astrophysical topics, from the properties of the Galactic disc to stellar evolution models. For this purpose, we need to know their chemical composition in detail. Unfortunately, the number of systems with chemical abundances determined from high resolution spectroscopy rema…