Search Publications
What controls the UV-to-X-ray continuum shape in quasars?
Brandt, W. N.; Laor, Ari; Timlin, John D., III
We present an investigation of the interdependence of the optical-to-X-ray spectral slope (αox), the He II equivalent-width (EW), and the monochromatic luminosity at 2500 Å (L2500). The values of αox and He II EW are indicators of the strength/shape of the quasar ionizing continuum, from the ultraviolet (UV; 1500-2…
Identification of AKARI infrared sources by the Deep HSC Optical Survey: construction of a new band-merged catalogue in the North Ecliptic Pole Wide field
Momose, Rieko; Hashimoto, Tetsuya; Goto, Tomotsugu +21 more
The North Ecliptic Pole field is a natural deep-field location for many satellite observations. It has been targeted many times since it was surveyed by the AKARI space telescope with its unique wavelength coverage from the near- to mid-infrared (mid-IR). Many follow-up observations have been carried out, making this field one of the most frequent…
Spectroscopy of the first resolved strongly lensed Type Ia supernova iPTF16geu
Cenko, S. B.; Kulkarni, S. R.; Nugent, P. E. +14 more
We report the results from spectroscopic observations of the multiple images of the strongly lensed Type Ia supernova (SN Ia), iPTF16geu, obtained with ground-based telescopes and the Hubble Space Telescope (HST). From a single epoch of slitless spectroscopy with HST, we resolve spectra of individual lensed supernova images for the first time. Thi…
Discovery and origins of giant optical nebulae surrounding quasar PKS 0454-22
Johnson, Sean D.; Chen, Hsiao-Wen; Greene, Jenny E. +1 more
We report optical integral-field spectroscopy in the field of one of the most luminous quasars in the z < 1 Universe, PKS 0454-22, with the Multi-Unit Spectroscopic Explorer. These data enable the discovery of three large ionized nebulae emitting in [O II], H β, and [O III] with projected areas of 1720, 1520, and 130 pkpc2, which we …
Stellar flares from blended and neighbouring stars in Kepler short cadence observations
Loyd, R. O. Parke; Jackman, James A. G.; Shkolnik, Evgenya
We present the results of a search for stellar flares from stars neighbouring the target sources in the Kepler short cadence data. These flares have been discarded as contaminants in previous surveys and therefore provide an unexplored resource of flare events, in particular high-energy events from faint stars. We have measured M dwarf flare energ…
Constraints on the [C II] luminosity of a proto-globular cluster at z ∼ 6 obtained with ALMA
Carniani, Stefano; Rosati, Piero; Meneghetti, Massimo +10 more
We report on ALMA observations of D1, a system at z ~ 6.15 with stellar mass $M_{*} \sim 10^7 \, \mathrm{M}_{\odot }$ containing globular cluster (GC) precursors, strongly magnified by the galaxy cluster MACS J0416.1-2403. Since the discovery of GC progenitors at high redshift, ours is the first attempt to probe directly the physical properties of…
The ultraluminous X-ray source bubble in NGC 5585
Motch, C.; Miller-Jones, J. C. A.; Soria, R. +4 more
Some ultraluminous X-ray sources (ULXs) are surrounded by collisionally ionized bubbles, larger and more energetic than supernova remnants: they are evidence of the powerful outflows associated with super-Eddington X-ray sources. We illustrate the most recent addition to this class: a huge (350 pc × 220 pc in diameter) bubble around a ULX in NGC 5…
Multiplicity among the cool supergiants in the Magellanic Clouds
Dorda, R.; Patrick, L. R.
The characterization of multiplicity of high-mass stars is of fundamental importance to understand their evolution, the diversity of observed core-collapse supernovae and the formation of gravitational wave progenitor systems. Despite that, until recently, one of the final phases of massive star evolution - the cool supergiant phase - has received…
Supernovae producing unbound binaries and triples
Kochanek, C. S.
The fraction of stars that are in binaries or triples at the time of stellar death and the fraction of these systems that survive the supernova explosion are crucial constraints for evolution models and predictions for gravitational wave source populations. These fractions are also subject to direct observational determination. Here, we search 10 …
Statistical microlensing towards magnified high-redshift star clusters
Dai, Liang
We study light variability of gravitationally magnified high-redshift star clusters induced by a foreground population of microlenses. This arises as the incoherent superposition of light variations from many source stars traversing the random magnification pattern on the source plane. The light curve resembles a scale-invariant, Gaussian process …