Search Publications
Optical spectroscopy of Gaia detected protostars with DOT: Can we probe protostellar photospheres?
Mathew, Blesson; Manoj, P.; Narang, Mayank +7 more
Optical spectroscopy offers the most direct view of the stellar properties and the accretion indicators. Standard accretion tracers, such as H
Internal kinematics of dwarf satellites of MW/M31-like galaxies in TNG50
van der Marel, Roeland P.; del Pino, Andrés; Aparicio, Antonio +2 more
We present a kinematic study of a thousand of dwarf satellites of MW/M31-like hosts from the IllustrisTNG50 simulation. Internal kinematics were derived for all the snapshots to obtain a historical record of their rotation velocity in the plane of the sky (|VT|) and the amplitude of their velocity gradients along the line of sight ($A_{…
Far-ultraviolet Dust Extinction and Molecular Hydrogen in the Diffuse Milky Way Interstellar Medium
Gordon, Karl D.; Van De Putte, Dries; Cartledge, Stefan I. B. +2 more
We aim to compare variations in the full-UV dust extinction curve (912-3000 Å), with the H I/H2/total H content along diffuse Milky Way sightlines, to investigate possible connections between ISM conditions and dust properties. We combine an existing sample of 75 UV extinction curves based on IUE and FUSE data, with atomic and molecular…
GTC Follow-up Observations of Very Metal-poor Star Candidates from DESI
Cunha, Katia; Smith, Verne V.; Moustakas, John +48 more
The observations from the Dark Energy Spectroscopic Instrument (DESI) will significantly increase the numbers of known extremely metal-poor stars by a factor of ~10, improving the sample statistics to study the early chemical evolution of the Milky Way and the nature of the first stars. In this paper we report follow-up observations with high sign…
Asteroseismology of double-mode radial δ Scuti stars: AE Ursae Majoris and RV Arietis
Daszyńska-Daszkiewicz, J.; Walczak, P.; Szewczuk, W. +1 more
We construct complex seismic models of two high-amplitude δ Sct stars, AE UMa and RV Ari, each pulsating in two radial modes: fundamental and first overtone. Besides the frequencies of two radial modes, the models also reproduce the amplitude of bolometric flux variations (the non-adiabatic parameter f) for the dominant mode. Applying the Monte-Ca…
HelioCast: heliospheric forecasting based on white-light observations of the solar corona
Poirier, Nicolas; Kouloumvakos, Athanasios; Indurain, Mikel +8 more
We present a new 3D magnetohydrodynamic (MHD) heliospheric model for space-weather forecasting driven by boundary conditions defined from white-light observations of the solar corona. The model is based on the MHD code PLUTO, constrained by an empirical derivation of the solar wind background properties at 0.1 au. This empirical method uses white-…
HALO7D. III. Chemical Abundances of Milky Way Halo Stars from Medium-resolution Spectra
Guhathakurta, Puragra; Kirby, Evan N.; Cunningham, Emily C. +4 more
The Halo Assembly in Lambda Cold Dark Matter: Observations in 7 Dimensions (HALO7D) survey measures the kinematics and chemical properties of stars in the Milky Way (MW) stellar halo to learn about the formation of our Galaxy. HALO7D consists of Keck II/DEIMOS spectroscopy and Hubble Space Telescope-measured proper motions of MW halo main-sequence…
Unveiling polarized emission from interstellar dust of the Large Magellanic Cloud with Planck
Hughes, A.; Alina, D.; Lazarian, A. +5 more
Polarization of interstellar dust emission is a powerful probe of dust properties and magnetic field structure. Yet studies of external galaxies are hampered by foreground dust contribution. The study aims at separating the polarized signal from the Large Magellanic Cloud (LMC) from that of the Milky Way (MW) to construct a wide-field, spatially c…
Planetary companions orbiting the M dwarfs GJ 724 and GJ 3988. A CARMENES and IRD collaboration
Kuzuhara, M.; Tamura, M.; Kudo, T. +36 more
We report the discovery of two exoplanets around the M dwarfs GJ 724 and GJ 3988 using the radial velocity (RV) method. We obtained a total of 153 3.5 m Calar Alto/CARMENES spectra for both targets and measured their RVs and activity indicators. We also added archival ESO/HARPS data for GJ 724 and infrared RV measurements from Subaru/IRD for GJ 39…
Discovery of the shell structure via break radii in the outer halo of the Milky Way
Shi, Jianrong; Ma, Jun; Ye, Dashuang +1 more
Based on the Gaia DR3 RR Lyrae catalogue, we use two methods to fit the density profiles with an improved broken power law, and find that there are two break radii coinciding with the two apocentre pile-ups of high-eccentricity Gaia-Sausage-Enceladus (GSE) merger. Also, there is a break caused by the Sagittarius (Sgr) stream. Combining the positio…