Search Publications
Data-driven selection and spectral classification of white dwarf stars
Bergeron, P.; Dufour, P.; Vincent, Olivier
The next generation of spectroscopic surveys is expected to provide spectra for hundreds of thousands of white dwarf (WD) candidates in the upcoming years. Currently, spectroscopic classification of white dwarfs is mostly done by visual inspection, requiring substantial amounts of expert attention. We propose a data-driven pipeline for fast, autom…
Redshifting galaxies from DESI to JWST CEERS: Correction of biases and uncertainties in quantifying morphology
Cheng, Cheng; Sun, Fengwu; Yu, Si-Yue +2 more
Observations of high-redshift galaxies with unprecedented detail have now been rendered possible with the James Webb Space Telescope (JWST). However, accurately quantifying their morphology remains uncertain due to potential biases and uncertainties. To address this issue, we used a sample of 1816 nearby DESI galaxies, with a stellar mass range of…
Origin and Extent of the Opacity Challenge for Atmospheric Retrievals of WASP-39 b
de Wit, Julien; Niraula, Prajwal; Gordon, Iouli E. +2 more
As the James Webb Space Telescope (JWST) came online last summer, we entered a new era of astronomy. This new era is supported by data products of unprecedented information content that require novel reduction and analysis techniques. Recently, Niraula et al. (N22) highlighted the need for upgraded opacity models to prevent facing a model-driven a…
Frequency analysis of the first-overtone RR Lyrae stars based on Extended Aperture Photometry from K2 data
Plachy, E.; Molnár, L.; Netzel, H. +1 more
Context. Additional low-amplitude signals have been observed in many RR Lyrae stars separate from pulsations in radial modes. The most common of these are short-period signals forming a period ratio of around 0.60-0.65 with the first overtone and long-period signals forming a period ratio of around 0.68. The RR Lyrae stars may also exhibit quasi-p…
Spatial and Binary Parameter Distributions of Black Hole Binaries in the Milky Way Detectable with Gaia
Shikauchi, Minori; Tanikawa, Ataru; Tsuna, Daichi +1 more
Soon after Gaia Data Release 3 (DR3) in 2022 June, some candidates (and one confirmed) of detached black hole (BH)-luminous companion (LC) binaries have been reported. Existing and future detections of astrometric BH-LC binaries will shed light on the spatial distribution of these systems, which can deepen our understanding of the natal kicks and …
Dust-scattering rings of GRB 221009A as seen by the Neil Gehrels Swift X-ray Observatory: can we count them all?
Vasilopoulos, Georgios; Karavola, Despina; Stathopoulos, Stamatios I. +1 more
We present the first results for the dust-scattering rings of GRB 221009A, coined as the gamma-ray bursts (GRBs) of the century, as observed by the Neil Gehrels Swift Observatory. We perform analysis of both time resolved observations and stacked data. The former approach enable us to study the expansion of the most prominent rings, associate thei…
The 300 pc Resolution Imaging of a z = 8.31 Galaxy: Turbulent Ionized Gas and Potential Stellar Feedback 600 Million Years after the Big Bang
Inoue, Akio K.; Hashimoto, Takuya; Sugahara, Yuma +16 more
We present the results of 300 pc resolution Atacama Large Millimeter/submillimeter Array imaging of the [O III] 88 µm line and dust continuum emission from a z = 8.312 Lyman-break galaxy MACS0416_Y1. The velocity-integrated [O III] emission has three peaks that are likely associated with three young stellar clumps of MACS0416_Y1, while the c…
Ejecta, Rings, and Dust in SN 1987A with JWST MIRI/MRS
Fox, O. D.; Blommaert, J. A. D. L.; Larsson, J. +31 more
Supernova (SN) 1987A is the nearest supernova in ~400 yr. Using the JWST MIRI Medium Resolution Spectrograph, we spatially resolved the ejecta, equatorial ring (ER), and outer rings in the mid-infrared 12,927 days (35.4 yr) after the explosion. The spectra are rich in line and dust continuum emission, both in the ejecta and the ring. The broad emi…
Magnetic Activity-Rotation-Age-Mass Relations in Late-pre-main-sequence Stars
Garmire, Gordon P.; Feigelson, Eric D.; Getman, Konstantin V.
We study the four-dimensional relationships between magnetic activity, rotation, mass, and age for solar-type stars in the age range 5-25 Myr. This is the late-pre-main-sequence (l-PMS) evolutionary phase when rapid changes in a star's interior may lead to changes in the magnetic dynamo mechanisms. We carefully derive rotational periods and spot s…
Ejecta Evolution Following a Planned Impact into an Asteroid: The First Five Weeks
Bannister, Michele T.; Guillot, Tristan; Abe, Lyu +85 more
The impact of the Double Asteroid Redirection Test spacecraft into Dimorphos, moon of the asteroid Didymos, changed Dimorphos's orbit substantially, largely from the ejection of material. We present results from 12 Earth-based facilities involved in a world-wide campaign to monitor the brightness and morphology of the ejecta in the first 35 days a…