Search Publications

X-ray eruptions every 22 days from the nucleus of a nearby galaxy
DOI: 10.1038/s41550-023-02178-4 Bibcode: 2024NatAs...8..347G

Gendreau, Keith; van Velzen, Sjoert; Gezari, Suvi +15 more

Galactic nuclei showing recurrent phases of activity and quiescence have recently been discovered. Some have recurrence times as short as a few hours to a day and are known as quasi-periodic X-ray eruption (QPE) sources. Others have recurrence times as long as hundreds to a thousand days and are called repeating nuclear transients. Here we present…

2024 Nature Astronomy
XMM-Newton 50
A More Precise Measurement of the Radius of PSR J0740+6620 Using Updated NICER Data
DOI: 10.3847/1538-4357/ad5f1e Bibcode: 2024ApJ...974..295D

Bogdanov, Slavko; Wolff, Michael T.; Arzoumanian, Zaven +9 more

PSR J0740+6620 is the neutron star with the highest precisely determined mass, inferred from radio observations to be 2.08 ± 0.07 M . Measurements of its radius therefore hold promise to constrain the properties of the cold, catalyzed, high-density matter in neutron star cores. Previously, Miller et al. and Riley et al. reported measur…

2024 The Astrophysical Journal
XMM-Newton 50
Evolution of the Size–Mass Relation of Star-forming Galaxies Since z = 5.5 Revealed by CEERS
DOI: 10.3847/1538-4357/ad20ed Bibcode: 2024ApJ...962..176W

Papovich, Casey; Finkelstein, Steven L.; Arrabal Haro, Pablo +19 more

We combine deep imaging data from the CEERS early release JWST survey and Hubble Space Telescope imaging from CANDELS to examine the size–mass relation of star-forming galaxies and the morphology–quenching relation at stellar masses M ≥ 109.5 M over the redshift range 0.5 < z < 5.5. In this study with a s…

2024 The Astrophysical Journal
Gaia eHST JWST 50
JWST Validates HST Distance Measurements: Selection of Supernova Subsample Explains Differences in JWST Estimates of Local H 0
DOI: 10.3847/1538-4357/ad8c21 Bibcode: 2024ApJ...977..120R

Casertano, Stefano; Filippenko, Alexei V.; Li, Siyang +16 more

We cross-check the Hubble Space Telescope (HST) Cepheid/Type Ia supernova (SN Ia) distance ladder, which yields the most precise local H 0, against early James Webb Space Telescope (JWST) subsamples (∼1/4 of the HST sample) from SH0ES and CCHP, calibrated only with NGC 4258. We find HST Cepheid distances agree well (∼1σ) with all combin…

2024 The Astrophysical Journal
eHST JWST 49
A massive interacting galaxy 510 million years after the Big Bang
DOI: 10.1038/s41550-024-02218-7 Bibcode: 2024NatAs...8..657B

Santini, Paola; Castellano, Marco; Fontana, Adriano +26 more

James Webb Space Telescope observations have spectroscopically confirmed the existence of galaxies as early as 300 Myr after the Big Bang and with a higher number density than what was expected based on galaxy formation models and Hubble Space Telescope observations. Yet, most sources confirmed spectroscopically so far in the first 500 Myr have re…

2024 Nature Astronomy
eHST JWST 49
The Initial Mass Function Based on the Full-sky 20 pc Census of ∼3600 Stars and Brown Dwarfs
DOI: 10.3847/1538-4365/ad24e2 Bibcode: 2024ApJS..271...55K

Tsai, Chao-Wei; Mamajek, Eric; Gonzales, Eileen C. +83 more

A complete accounting of nearby objects—from the highest-mass white dwarf progenitors down to low-mass brown dwarfs—is now possible, thanks to an almost complete set of trigonometric parallax determinations from Gaia, ground-based surveys, and Spitzer follow-up. We create a census of objects within a Sun-centered sphere of 20 pc radius and check p…

2024 The Astrophysical Journal Supplement Series
Gaia 49
Possible Hycean conditions in the sub-Neptune TOI-270 d
DOI: 10.1051/0004-6361/202348238 Bibcode: 2024A&A...683L...2H

Madhusudhan, Nikku; Holmberg, Måns

The JWST has ushered in a new era in atmospheric characterisations of temperate low-mass exoplanets with recent detections of carbon-bearing molecules in the candidate Hycean world K2-18 b. We investigated JWST observations of the TOI-270 system, with two sub-Neptunes simultaneously transiting the nearby M dwarf during the visit. We report our atm…

2024 Astronomy and Astrophysics
eHST JWST 49
The UNCOVER Survey: A First-look HST+JWST Catalog of Galaxy Redshifts and Stellar Population Properties Spanning 0.2 ≲ z ≲ 15
DOI: 10.3847/1538-4365/ad0846 Bibcode: 2024ApJS..270...12W

Papovich, Casey; Franx, Marijn; Muzzin, Adam +41 more

The recent UNCOVER survey with the James Webb Space Telescope (JWST) exploits the nearby cluster A2744 to create the deepest view of our Universe to date by leveraging strong gravitational lensing. In this work, we perform photometric fitting of more than 50,000 robustly detected sources out to z ~ 15. We show the redshift evolution of stellar age…

2024 The Astrophysical Journal Supplement Series
eHST JWST 49
Cygnus X-3 revealed as a Galactic ultraluminous X-ray source by IXPE
DOI: 10.1038/s41550-024-02294-9 Bibcode: 2024NatAs...8.1031V

Ingram, Adam; Kaaret, Philip; Wu, Kinwah +127 more

The accretion of matter by compact objects can be inhibited by radiation pressure if the luminosity exceeds a critical value known as the Eddington limit. The discovery of ultraluminous X-ray sources has shown that accretion can proceed even when the apparent luminosity considerably exceeds this limit. A high apparent luminosity might be produced …

2024 Nature Astronomy
INTEGRAL 48
The more the merrier: SRG/eROSITA discovers two further galaxies showing X-ray quasi-periodic eruptions
DOI: 10.1051/0004-6361/202348881 Bibcode: 2024A&A...684A..64A

Gromadzki, M.; Salvato, M.; Liu, Z. +20 more

X-ray quasi-periodic eruptions (QPEs) are a novel addition to the group of extragalactic transients. With only a select number of known sources, and many more models published trying to explain them, we are so far limited in our understanding by small number statistics. In this work, we report the discovery of two further galaxies showing QPEs, he…

2024 Astronomy and Astrophysics
Gaia XMM-Newton 48