Search Publications
HST/WFC3 Hα Direct-imaging Detection of a Pointlike Source in the Disk Cavity of AB Aur
Zhou, Yifan; Kraus, Adam L.; Bae, Jaehan +8 more
Accreting protoplanets enable the direct characterization of planet formation. As part of a high-contrast imaging search for accreting planets with the Hubble Space Telescope (HST) Wide Field Camera 3, we present Hα images of AB Aurigae (AB Aur), a Herbig Ae/Be star harboring a transition disk. The data were collected in two epochs of direct-imagi…
A persistent ultraviolet outflow from an accreting neutron star binary transient
Díaz Trigo, M.; Altamirano, D.; Knigge, C. +31 more
All disc-accreting astrophysical objects produce powerful disc winds. In compact binaries containing neutron stars or black holes, accretion often takes place during violent outbursts. The main disc wind signatures during these eruptions are blue-shifted X-ray absorption lines, which are preferentially seen in disc-dominated `soft states'1,2<…
Observation of a Magnetic Switchback in the Solar Corona
Telloni, Daniele; Zank, Gary P.; Adhikari, Laxman +58 more
Switchbacks are sudden, large radial deflections of the solar wind magnetic field, widely revealed in interplanetary space by the Parker Solar Probe. The switchbacks' formation mechanism and sources are still unresolved, although candidate mechanisms include Alfvénic turbulence, shear-driven Kelvin-Helmholtz instabilities, interchange reconnection…
Stellar metallicity gradients of Local Group dwarf galaxies
Jablonka, P.; Battaglia, G.; Taibi, S. +5 more
Aims: We explore correlations between the strength of metallicity gradients in Local Group dwarf galaxies and their stellar mass, star formation history timescales, and environment.
Methods: We performed a homogeneous analysis of literature spectroscopic data of red giant stars and determined radial metallicity profiles for 30 Local Grou…
Red Spiral Galaxies at Cosmic Noon Unveiled in the First JWST Image
Inoue, Akio K.; Sugahara, Yuma; Fudamoto, Yoshinobu
In the first image of the James Webb Space Telescope (JWST) of SMACS J0723.3-7327, one of the most outstanding features is the emergence of a large number of red spiral galaxies, because such red spiral galaxies are only a few percent in the number fraction among nearby spiral galaxies. While these apparently red galaxies were already detected wit…
TOI-1452 b: SPIRou and TESS Reveal a Super-Earth in a Temperate Orbit Transiting an M4 Dwarf
Latham, David W.; Tamura, Motohide; Stassun, Keivan G. +53 more
Exploring the properties of exoplanets near or inside the radius valley provides insight on the transition from the rocky super-Earths to the larger, hydrogen-rich atmosphere mini-Neptunes. Here, we report the discovery of TOI-1452b, a transiting super-Earth (R p = 1.67 ± 0.07 R ⊕) in an 11.1 day temperate orbit (T eq
Opening the Era of Quasar-host Studies at High Redshift with JWST
Onoue, Masafusa; Silverman, John D.; Ding, Xuheng
We measure the host galaxy properties of five quasars with z ~ 1.6-3.5 selected from the Sloan Digital Sky Survey (SDSS) and AEGIS, which fall within the JWST/Hubble Space Telescope (HST) CEERS survey area. A point-spread function library is constructed based on stars in the full field of view of the data and used with the 2D image modeling tool g…
Metallicities in M dwarfs: Investigating different determination techniques
Amado, P. J.; Caballero, J. A.; Reiners, A. +17 more
Deriving metallicities for solar-like stars follows well-established methods, but for cooler stars such as M dwarfs, the determination is much more complicated due to forests of molecular lines that are present. Several methods have been developed in recent years to determine accurate stellar parameters for these cool stars (Teff ≲ 4000…
Primordial non-Gaussianity from the completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey II: measurements in Fourier space with optimal weights
Brownstein, Joel R.; Palanque-Delabrouille, Nathalie; Schneider, Donald P. +12 more
We present measurements of the local primordial non-Gaussianity parameter $f_{\mathrm{NL}}^\mathrm{local} $from the clustering of 343 708 quasars with redshifts 0.8 < z < 2.2 distributed over 4808 deg2 from the final data release (DR16) of the extended Baryon Acoustic Oscillation Spectroscopic Survey (eBOSS), the largest volume sp…
The iron and oxygen content of LMC Classical Cepheids and its implications for the extragalactic distance scale and Hubble constant. Equivalent width analysis with Kurucz stellar atmosphere models
Mucciarelli, Alessio; Riess, Adam; Yuan, Wenlong +6 more
Context. Classical Cepheids are primary distance indicators and a crucial stepping stone in determining the present-day value of the Hubble constant H0 to the precision and accuracy required to constrain apparent deviations from the ΛCDM Concordance Cosmological Model.
Aims: We measured the iron and oxygen abundances of a statistic…