Search Publications

A Multiwavelength Survey of Nearby M Dwarfs: Optical and Near-ultraviolet Flares and Activity with Contemporaneous TESS, Kepler/K2, Swift, and HST Observations
DOI: 10.3847/1538-4357/ad487d Bibcode: 2024ApJ...971...24P

Barclay, Thomas; Kowalski, Adam F.; Tristan, Isaiah I. +14 more

We present a comprehensive multiwavelength investigation into flares and activity in nearby M dwarf stars. We leverage the most extensive contemporaneous data set obtained through the Transiting Exoplanet Sky Survey, Kepler/K2, the Neil Gehrels Swift Observatory, and the Hubble Space Telescope, spanning the optical and near-ultraviolet (NUV) regim…

2024 The Astrophysical Journal
eHST 7
Supervirial hot phase in Milky Way circumgalactic medium: further evidences
DOI: 10.1093/mnras/stad3497 Bibcode: 2024MNRAS.527.5093M

Mathur, Smita; Gupta, Anjali; Das, Sanskriti +2 more

Recent discoveries of a supervirial hot phase of the Milky Way circumgalactic medium (CGM) have launched new questions regarding the multiphase structure of the CGM around the Galaxy. We use 1.05 Ms of archival Chandra/high-energy transmission grating observations to characterize highly ionized metal absorption at z = 0 along the line of sight of …

2024 Monthly Notices of the Royal Astronomical Society
XMM-Newton 7
Lyman Continuum Emission from Active Galactic Nuclei at 2.3 ≲ z ≲ 3.7 in the UVCANDELS Fields
DOI: 10.3847/1538-4357/ad1ef0 Bibcode: 2024ApJ...964...73S

Dickinson, Mark; Grogin, Norman A.; Hathi, Nimish P. +19 more

We present the results of our search for Lyman continuum (LyC)-emitting (weak) active galactic nuclei (AGN) at redshifts 2.3 ≲ z ≲ 4.9 from Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) F275W observations in the Ultraviolet Imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (UVCANDELS) fields. We also include L…

2024 The Astrophysical Journal
Herschel eHST 7
Unveiling Luminous Lyα Emitters at z ≈ 6 through JWST/NIRCam Imaging in the COSMOS Field
DOI: 10.3847/2041-8213/ad292f Bibcode: 2024ApJ...963L..38N

Ning, Yuanhang; Cai, Zheng; Lin, Xiaojing +7 more

We study a sample of 14 spectroscopically confirmed Lyα emitters (LAEs) in the late era of reionization (at redshift z ≈ 6) based on the JWST/NIRCam imaging data set. These LAEs with high Lyα luminosity of L(Lyα) ∼1042.4–1043.4 erg s‑1 have been covered by the (ongoing) COSMOS-Web survey over 0.28 deg2 i…

2024 The Astrophysical Journal
JWST 7
SN 2020pvb: A Type IIn-P supernova with a precursor outburst
DOI: 10.1051/0004-6361/202348790 Bibcode: 2024A&A...686A..13E

Lundqvist, P.; Gal-Yam, A.; Geier, S. +37 more

We present photometric and spectroscopic datasets for SN 2020pvb, a Type IIn-P supernova (SN) that is similar to SNe 1994W, 2005cl, 2009kn, and 2011ht, with a precursor outburst detected (PS1 w band ∼-13.8 mag) around four months before the B-band maximum light. SN 2020pvb presents a relatively bright light curve that peaked at MB = −17…

2024 Astronomy and Astrophysics
eHST 7
Methane emission from a cool brown dwarf
DOI: 10.1038/s41586-024-07190-w Bibcode: 2024Natur.628..511F

Kiman, Rocio; Kirkpatrick, J. Davy; Gelino, Christopher R. +21 more

Beyond our Solar System, aurorae have been inferred from radio observations of isolated brown dwarfs1,2. Within our Solar System, giant planets have auroral emission with signatures across the electromagnetic spectrum including infrared emission of H3+ and methane. Isolated brown dwarfs with auroral signatures in t…

2024 Nature
JWST 7
Large exomoons unlikely around Kepler-1625 b and Kepler-1708 b
DOI: 10.1038/s41550-023-02148-w Bibcode: 2024NatAs...8..193H

Heller, René; Hippke, Michael

There are more than 200 moons in our Solar System, but their relatively small radii make similarly sized extrasolar moons very hard to detect with current instruments. The best exomoon candidates so far are two nearly Neptune-sized bodies orbiting the Jupiter-sized transiting exoplanets Kepler-1625 b and Kepler-1708 b, but their existence has been…

2024 Nature Astronomy
eHST 7
A survey for radio emission from white dwarfs in the VLA Sky Survey
DOI: 10.1093/mnras/stae1275 Bibcode: 2024MNRAS.531.1805P

Dhillon, V. S.; Strader, Jay; Dage, Kristen C. +22 more

Radio emission has been detected from tens of white dwarfs, in particular in accreting systems. Additionally, radio emission has been predicted as a possible outcome of a planetary system around a white dwarf. We searched for 3 GHz radio continuum emission in 846 000 candidate white dwarfs previously identified in Gaia using the Very Large Array S…

2024 Monthly Notices of the Royal Astronomical Society
Gaia XMM-Newton 7
Axisymmetric High Spot Coverage on Exoplanet Host HD 189733 A
DOI: 10.3847/1538-3881/ad1f6c Bibcode: 2024AJ....167..107N

Rackham, Benjamin V.; de Wit, Julien; Narrett, Isaac S.

Transmission spectroscopy is a powerful tool to study exoplanet atmospheres, which can be affected by the ability of stellar photospheric heterogeneity to mimic or mask exoplanetary spectral signatures. The canonical HD 189733 system provides a textbook example of this spectroscopic discrepancy with features that have been variously interpreted as…

2024 The Astronomical Journal
Gaia eHST 7
Coordinated JWST Imaging of Three Distance Indicators in a Supernova Host Galaxy and an Estimate of the Tip of the Red Giant Branch Color Dependence
DOI: 10.3847/1538-4357/ad7952 Bibcode: 2024ApJ...975..111H

Madore, Barry F.; Freedman, Wendy L.; Jang, In Sung +3 more

Boasting a 6.5 m mirror in space, JWST can increase by several times the number of supernovae (SNe) to which a redshift-independent distance has been measured with a precision distance indicator (e.g., tip of the red giant branch (TRGB) or Cepheids); the limited number of such SN calibrators currently dominates the uncertainty budget in distance l…

2024 The Astrophysical Journal
eHST JWST 7