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Chemical abundances and radial velocities in the extremely metal-poor galaxy DDO 68
Tosi, M.; Bellazzini, M.; Cusano, F. +9 more
We present chemical abundances and radial velocities of six H II regions in the extremely metal-poor star-forming dwarf galaxy DDO 68. They are derived from deep spectra in the wavelength range 3500-10 000 Å, acquired with the Multi-Object Double Spectrograph at the Large Binocular Telescope (LBT). In the three regions where the [O III] λ4363 Å li…
Multi-component Decomposition of Astronomical Spectra by Compressed Sensing
Winebarger, Amy R.; Antolin, Patrick; Testa, Paola +9 more
The signal measured by an astronomical spectrometer may be due to radiation from a multi-component mixture of plasmas with a range of physical properties (e.g., temperature, Doppler velocity). Confusion between multiple components may be exacerbated if the spectrometer sensor is illuminated by overlapping spectra dispersed from different slits, wi…
Not So Heavy Metals: Black Hole Feedback Enriches the Circumgalactic Medium
Werk, Jessica K.; Pontzen, Andrew; Christensen, Charlotte +4 more
We examine the effects of supermassive black hole (SMBH) feedback on the circumgalactic medium (CGM) using a cosmological hydrodynamic simulation (ROMULUS25) and a set of four zoom-in “genetically modified” Milky-Way-mass galaxies sampling different evolutionary paths. By tracing the distribution of metals in the CGM, we show that O VI is a sensit…
Hubble Space Telescope Flux Calibration. I. STIS and CALSPEC
Bohlin, Ralph C.; Deustua, Susana E.; de Rosa, Gisella
The precision of absolute flux measurements is quantified for the Space Telescope Imaging Spectrograph (STIS), which is the most important contributor to the CALSPEC standards. With our goal of 1% absolute accuracy, the documentation of the Hubble Space Telescope/CALSPEC flux scale and its subpercent repeatability are of prime importance. While th…
A resonant pair of warm giant planets revealed by TESS
Torres, Guillermo; Nesvorný, David; Kipping, David +4 more
We present the discovery of a pair of transiting giant planets using four sectors of TESS photometry. TOI-216 is a 0.87 M⊙ dwarf orbited by two transiters with radii of 8.2 and 11.3 R⊕, and periods of 17.01 and 34.57 d, respectively. Anticorrelated TTVs are clearly evident indicating that the transiters orbit the same star an…
Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. X. Optical Variability Characteristics
Ho, Luis C.; Bian, Wei-Hao; Zhang, Zhi-Xiang +11 more
We compiled a sample of 73 active galactic nuclei (AGNs) with reverberation mapping (RM) observations from RM campaigns, including our ongoing campaign of monitoring super-Eddington accreting massive black holes (BHs). This sample covers a large range of BH mass ({M}\bullet ={10}6{--9} {M}⊙ ), dimensionless accreti…
Probing cosmic dawn: modelling the assembly history, SEDs, and dust content of selected z ∼ 9 galaxies
Ellis, Richard S.; Laporte, Nicolas; Devriendt, Julien +2 more
The presence of spectroscopically confirmed Balmer breaks in galaxy spectral energy distributions (SEDs) at z > 9 provides one of the best probes of the assembly history of the first generations of stars in our Universe. Recent observations of the gravitationally lensed source, MACS 1149_JD1 (JD1), indicate that significant amounts of star form…
Quiescent Galaxy Size and Spectroscopic Evolution: Combining HSC Imaging and Hectospec Spectroscopy
Geller, Margaret J.; Utsumi, Yousuke; Damjanov, Ivana +3 more
We explore the relationships between size, stellar mass, and average stellar population age (indicated by D n 4000 indices) for a sample of ∼11,000 intermediate-redshift galaxies from the SHELS spectroscopic survey (Geller et al. 2014) augmented by high-resolution Subaru Telescope Hyper Suprime-Cam imaging. In the redshift interval 0.1…
Quasar Sightline and Galaxy Evolution (QSAGE) survey - I. The galaxy environment of O VI absorbers up to z = 1.4 around PKS 0232-04
Cullen, F.; Bower, R. G.; Tejos, N. +8 more
We present the first results from a study of O VI absorption around galaxies at z < 1.44 using data from a near-infrared grism spectroscopic Hubble Space Telescope Large Programme, the Quasar Sightline and Galaxy Evolution (QSAGE) survey. QSAGE is the first grism galaxy survey to focus on the circumgalactic medium at z ∼ 1, providing a blind su…
Evolutionary phases of merging clusters as seen by LOFAR
Brunetti, G.; Shimwell, T. W.; Cassano, R. +13 more
Massive, merging galaxy clusters often host giant, diffuse radio sources that arise from shocks and turbulence; hence, radio observations can be useful for determining the merger state of a cluster. In preparation for a larger study, we selected three clusters - Abell 1319, Abell 1314, and RXC J1501.3+4220 (Z7215) - making use of the new LOFAR Two…