Search Publications
Resolving the Soft X-Ray Ultrafast Outflow in PDS 456
Reeves, J. N.; Braito, V.; Nardini, E. +3 more
Past X-ray observations of the nearby luminous quasar PDS 456 (at z = 0.184) have revealed a wide-angle accretion disk wind with an outflow velocity of ∼-0.25c, as observed through observations of its blueshifted iron K-shell absorption line profile. Here we present three new XMM-Newton observations of PDS 456: one in 2018 September where the quas…
Solar System Physics for Exoplanet Research
Löhne, T.; Marshall, J. P.; Dalba, P. A. +13 more
Over the past three decades, we have witnessed one of the great revolutions in our understanding of the cosmos—the dawn of the Exoplanet Era. Where once we knew of just one planetary system (the solar system), we now know of thousands, with new systems being announced on a weekly basis. Of the thousands of planetary systems we have found to date, …
A Census of Sub-kiloparsec Resolution Metallicity Gradients in Star-forming Galaxies at Cosmic Noon from HST Slitless Spectroscopy
Teplitz, Harry I.; Schmidt, Kasper B.; Treu, Tommaso +12 more
We present the hitherto largest sample of gas-phase metallicity radial gradients measured at sub-kpc resolution in star-forming galaxies in the redshift range of z ∈ [1.2, 2.3]. These measurements are enabled by the synergy of slitless spectroscopy from the Hubble Space Telescope near-infrared channels and the lensing magnification from foreground…
The IACOB project. VI. On the elusive detection of massive O-type stars close to the ZAMS
Meynet, G.; Lennon, D. J.; Herrero, A. +7 more
Context. The apparent lack of massive O-type stars near the zero-age main sequence, or ZAMS (at ages <2 Myr), is a topic that has been widely discussed in the past 40 yr. Different explanations for the elusive detection of these young massive stars have been proposed from the observational and theoretical side, but no firm conclusions have been…
Physical Parameters of Late-type Contact Binaries in the Northern Catalina Sky Survey
Deng, Licai; de Grijs, Richard; Chen, Xiaodian +1 more
We present the physical parameters of 2335 late-type contact binary (CB) systems extracted from the Catalina Sky Survey (CSS). Our sample was selected from the CSS Data Release 1 by strictly limiting the prevailing temperature uncertainties and light-curve fitting residuals, allowing us to almost eliminate any possible contaminants. We developed a…
Discovery and astrophysical properties of Galactic open clusters in dense stellar fields using Gaia DR2
Corradi, W. J. B.; Ferreira, F. A.; Maia, F. F. S. +2 more
We report the discovery of 25 new open clusters resulting from a search in dense low Galactic latitude fields. We also provide, for the first time, structural and astrophysical parameters for the new findings and 34 other recently discovered open clusters using Gaia Data Release 2 (DR2) data. The candidates were confirmed by jointly inspecting the…
The evolution of rest-frame UV properties, Ly α EWs, and the SFR-stellar mass relation at z ∼ 2-6 for SC4K LAEs
da Cunha, E.; Arrabal Haro, P.; Sobral, D. +6 more
We explore deep rest-frame UV to FIR data in the COSMOS field to measure the individual spectral energy distributions (SED) of the ∼4000 SC4K (Sobral et al.) Lyman α (Ly α) emitters (LAEs) at z ∼ 2-6. We find typical stellar masses of 109.3 ± 0.6 M⊙ and star formation rates (SFR) of SFR_SED=4.4^{+10.5}_{-2.4} M⊙ yr…
Superflares and variability in solar-type stars with TESS in the Southern hemisphere
Doyle, J. G.; Ramsay, G.; Doyle, L.
Superflares on solar-type stars have been a rapidly developing field ever since the launch of Kepler. Over the years, there have been several studies investigating the statistics of these explosive events. In this study, we present a statistical analysis of stellar flares on solar-type stars made using photometric data in 2-min cadence from Transi…
Multiple chemodynamic stellar populations of the Ursa Minor dwarf spheroidal galaxy
Djorgovski, S. G.; Geha, Marla; Simon, Joshua D. +6 more
We present a Bayesian method to identify multiple (chemodynamic) stellar populations in dwarf spheroidal galaxies (dSphs) using velocity, metallicity, and positional stellar data without the assumption of spherical symmetry. We apply this method to a new Keck/Deep Imaging Multi-Object Spectrograph (DEIMOS) spectroscopic survey of the Ursa Minor (U…
Stellar Feedback and Resolved Stellar IFU Spectroscopy in the Nearby Spiral Galaxy NGC 300
Kruijssen, J. M. Diederik; Longmore, Steven N.; Chevance, Mélanie +7 more
We present MUSE integral field unit (IFU) observations of five individual H II regions in two giant star-forming complexes in the low-metallicity, nearby dwarf spiral galaxy NGC 300. In combination with high spatial resolution Hubble Space Telescope photometry, we demonstrate the extraction of stellar spectra and classification of individual stars…