Search Publications
Fourteen candidate RR Lyrae star streams in the inner Galaxy
Kawata, Daisuke; Mateu, Cecilia; Read, Justin I.
We apply the GC3 stream-finding method to RR Lyrae stars (RRLSs) in the Catalina survey. We find 2 RRLS stream candidates at >4σ confidence and another 12 at >3.5σ confidence over the Galactocentric distance range 4 < D/kpc < 26. Of these, only two are associated with known globular clusters (NGC 1261 and Arp2). The remainder are candi…
Calibrating the metallicity of M dwarfs in wide physical binaries with F-, G-, and K-primaries - I: High-resolution spectroscopy with HERMES: stellar parameters, abundances, and kinematics
Alonso-Floriano, F. J.; Caballero, J. A.; Montes, D. +7 more
We investigated almost 500 stars distributed among 193 binary or multiple systems made of late-F, G-, or early-K-primaries and late-K- or M-dwarf companion candidates. For all of them, we compiled or measured coordinates, J-band magnitudes, spectral types, distances, and proper motions. With these data, we established a sample of 192 physically bo…
The mean ultraviolet spectrum of a representative sample of faint z ∼ 3 Lyman alpha emitters
Ellis, Richard S.; Robertson, Brant E.; Nakajima, Kimihiko +2 more
We discuss the rest-frame ultraviolet (UV) emission line spectra of a large (∼100) sample of low luminosity redshift z ∼ 3.1 Lyman alpha emitters (LAEs) drawn from a Subaru imaging survey in the SSA22 survey field. Our earlier work based on smaller samples indicated that such sources have high [O III]/[O II] line ratios possibly arising from a har…
Ultrafast outflows disappear in high-radiation fields
Fabian, A. C.; Reynolds, C. S.; Pinto, C. +8 more
Ultrafast outflows (UFOs) are the most extreme winds launched by active galactic nuclei (AGN) due to their mildly relativistic speeds (∼0.1-0.3c) and are thought to significantly contribute to galactic evolution via AGN feedback. Their nature and launching mechanism are however not well understood. Recently, we have discovered the presence of a va…
Revisiting hypervelocity stars after Gaia DR2
Evans, N. W.; Hawkins, K.; Strader, J. +3 more
Hypervelocity stars are intriguing rare objects travelling at speeds large enough to be unbound from the Milky Way. Several mechanisms have been proposed for producing them, including the interaction of the Galaxy's supermassive black hole (SMBH) with a binary; rapid mass-loss from a companion to a star in a short-period binary; the tidal disrupti…
Testing the Larson relations in massive clumps
Peretto, N.; Elia, D.; Schisano, E. +6 more
We tested the validity of the three Larson relations in a sample of 213 massive clumps selected from the Herschel infrared Galactic Plane (Hi-GAL) survey, also using data from the Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey of 3-mm emission lines. The clumps are divided into five evolutionary stages so that we can also discuss the Lars…
Major merging history in CANDELS. I. Evolution of the incidence of massive galaxy-galaxy pairs from z = 3 to z ∼ 0
Finkelstein, Steven L.; Barro, Guillermo; Pérez-González, Pablo G. +37 more
The rate of major galaxy-galaxy merging is theoretically predicted to steadily increase with redshift during the peak epoch of massive galaxy development (1 ≤ z ≤ 3). We use close-pair statistics to objectively study the incidence of massive galaxies (stellar M1 > 2 × 1010 M⊙) hosting major companions (1 ≤ M
Likely transiting exocomets detected by Kepler
Vanderburg, A.; Kraus, A.; Rappaport, S. +8 more
We present the first good evidence for exocomet transits of a host star in continuum light in data from the Kepler mission. The Kepler star in question, KIC 3542116, is of spectral type F2V and is quite bright at Kp = 10. The transits have a distinct asymmetric shape with a steeper ingress and slower egress that can be ascribed to objects with a t…
The ultraviolet spectroscopic evolution of the low-luminosity tidal disruption event iPTF16fnl
Kochanek, C. S.; Stanek, K. Z.; Shappee, B. J. +14 more
We present the ultraviolet (UV) spectroscopic evolution of a tidal disruption event (TDE) for the first time. After the discovery of the nearby TDE iPTF16fnl, we obtained a series of observations with the Space Telescope Imaging Spectrograph (STIS) onboard the Hubble Space Telescope (HST). The dominant emission features closely resemble those seen…
MAHALO Deep Cluster Survey I. Accelerated and enhanced galaxy formation in the densest regions of a protocluster at z = 2.5
Prochaska, J. Xavier; Cai, Zheng; Suzuki, Tomoko L. +6 more
We carried out deep H α narrowband imaging with 10 h net integrations towards the young protocluster, USS1558-003 at z = 2.53 with the Subaru Telescope. This system is composed of four dense groups with massive local overdensities, traced by 107 H α emitters (HAEs) with stellar masses and dust-corrected star formation rates down to 1 × 108