Search Publications
Strong damped Lyman-α absorption in young star-forming galaxies at redshifts 9 to 11
Finkelstein, Steven L.; Arrabal Haro, Pablo; Heintz, Kasper E. +18 more
Primordial neutral atomic gas, mostly composed of hydrogen, is the raw material for star formation in galaxies. However, there are few direct constraints on the amount of neutral atomic hydrogen (H I) in galaxies at early cosmic times. We analyzed James Webb Space Telescope (JWST) near-infrared spectroscopy of distant galaxies, at redshifts ≳8. Fr…
A pulsar in a binary with a compact object in the mass gap between neutron stars and black holes
Cadelano, Mario; Pallanca, Cristina; Freire, Paulo C. C. +22 more
Some compact objects observed in gravitational wave events have masses in the gap between known neutron stars (NSs) and black holes (BHs). The nature of these mass gap objects is unknown, as is the formation of their host binary systems. We report pulsar timing observations made with the Karoo Array Telescope (MeerKAT) of PSR J0514‑4002E, an eccen…
Emission lines due to ionizing radiation from a compact object in the remnant of Supernova 1987A
Fox, O. D.; Blommaert, J. A. D. L.; Larsson, J. +31 more
The nearby Supernova 1987A was accompanied by a burst of neutrino emission, which indicates that a compact object (a neutron star or black hole) was formed in the explosion. There has been no direct observation of this compact object. In this work, we observe the supernova remnant with JWST spectroscopy, finding narrow infrared emission lines of a…
A magnetic massive star has experienced a stellar merger
Smoker, J. V.; Shenar, T.; Sana, H. +13 more
Massive stars (those ≥8 solar masses at formation) have radiative envelopes that cannot sustain a dynamo, the mechanism that produces magnetic fields in lower-mass stars. Despite this, approximately 7% of massive stars have observed magnetic fields, the origin of which is debated. We used multi-epoch interferometric and spectroscopic observations …
Sun-like stars produce superflares roughly once per century
Solanki, Sami K.; Notsu, Yuta; Maehara, Hiroyuki +7 more
Stellar superflares are energetic outbursts of electromagnetic radiation that are similar to solar flares but release more energy, up to 1036 erg on main-sequence stars. It is unknown whether the Sun can generate superflares and, if so, how often they might occur. We used photometry from the Kepler space observatory to investigate super…