Search Publications
Rotation and Abundances of the Benchmark Brown Dwarf HD 33632 Ab from Keck/KPIC High-resolution Spectroscopy
Fitzgerald, Michael P.; López, Ronald A.; Skemer, Andrew +24 more
We present the projected rotational velocity and molecular abundances for HD 33632 Ab obtained via Keck Planet Imager and Characterizer (KPIC) high-resolution spectroscopy. HD 33632 Ab is a nearby benchmark brown dwarf companion at a separation of ∼20 au that straddles the L–T transition. Using a forward-modeling framework with on-axis host star s…
White Dwarf Merger Remnants: The DAQ Subclass
Blouin, Simon; Bergeron, Pierre; Kilic, Mukremin +3 more
Four years after the discovery of a unique DAQ white dwarf with a hydrogen-dominated and carbon-rich atmosphere, we report the discovery of four new DAQ white dwarfs, including two that were not recognized properly in the literature. We find all five DAQs in a relatively narrow mass and temperature range of M = 1.14–1.19 M ⊙ and T …
Exploring reheated sub-40000 Kelvin neutron stars with JWST, ELT, and TMT
Raj, Nirmal; Shivanna, Prajwal; Rachh, Gaurav Niraj
Neutron stars cooling passively since their birth may be reheated in their late-stage evolution by a number of possible phenomena; rotochemical, vortex creep, crust cracking, magnetic field decay, or more exotic processes such as removal of neutrons from their Fermi seas (the nucleon Auger effect), baryon number-violating nucleon decay, and accret…
Bayesian analysis of the molecular emission and dust continuum of protoplanetary disks
Woitke, P.; Kamp, I.; Min, M. +2 more
Context. The MIRI instrument on board the James Webb Space Telescope probes the chemistry and dust mineralogy of the inner regions of protoplanetary disks. The observed spectra are unprecedented in their detail and reveal a rich chemistry with strong diversity between objects. This complicates interpretations that are mainly based on manual contin…
The detection of polarized X-ray emission from the magnetar 1E 2259+586
Kaaret, Philip; Wu, Kinwah; Enoto, Teruaki +98 more
We report on IXPE, NICER, and XMM-Newton observations of the magnetar 1E 2259+586. We find that the source is significantly polarized at about or above 20 per cent for all phases except for the secondary peak where it is more weakly polarized. The polarization degree is strongest during the primary minimum which is also the phase where an absorpti…
PHANGS-HST Catalogs for ∼100,000 Star Clusters and Compact Associations in 38 Galaxies. I. Observed Properties
Leroy, Adam K.; Rosolowsky, Erik; Klessen, Ralf S. +25 more
We present the largest catalog to date of star clusters and compact associations in nearby galaxies. We have performed a V-band-selected census of clusters across the 38 spiral galaxies of the PHANGS–Hubble Space Telescope (HST) Treasury Survey, and measured integrated, aperture-corrected near-ultraviolet-U-B-V-I photometry. This work has resulted…
An optical gamma-ray burst catalogue with measured redshift - I. Data release of 535 gamma-ray bursts and colour evolution
Butler, N. R.; Cenko, S. B.; Lee, W. H. +49 more
We present the largest optical photometry compilation of gamma-ray bursts (GRBs) with redshifts (z). We include 64813 observations of 535 events (including upper limits) from 28 February 1997 to 18 August 2023. We also present a user-friendly web tool grbLC which allows users to visualize photometry, coordinates, redshift, host galaxy extinction, …
JWST detections of amorphous and crystalline HDO ice toward massive protostars
Manoj, P.; Narang, Mayank; Bourke, Tyler L. +19 more
Context. Tracing the origin and evolution of interstellar water is key to understanding many of the physical and chemical processes involved in star and planet formation. Deuterium fractionation offers a window into the physicochemical history of water due to its sensitivity to local conditions.
Aims: The aim of this work is to utilize the in…
Cepheids as distance indicators and stellar tracers
Bono, G.; Pietrinferni, A.; Braga, V. F.
We review the phenomenology of classical Cepheids (CCs), Anomalous Cepheids (ACs) and type II Cepheids (TIICs) in the Milky Way (MW) and in the Magellanic Clouds (MCs). We also examine the Hertzsprung progression in different stellar systems by using the shape of I-band light curves (Fourier parameters) and observables based on the difference in m…
First JWST Observations of JAGB Stars in the SN Ia Host Galaxies: NGC 7250, NGC 4536, NGC 3972
Madore, Barry F.; Freedman, Wendy L.; Jang, In Sung +2 more
The J-region Asymptotic Giant Branch (JAGB) method is a standard candle that leverages the constant luminosities of color-selected, carbon-rich AGB stars, measured in the near-infrared at 1.2 µm. The Chicago-Carnegie Hubble Program has obtained JWST imaging of the SN Ia host galaxies NGC 7250, NGC 4536, and NGC 3972. With these observations,…