Search Publications
The origin of the observed Ly α EW distribution of dwarf galaxies at z 2
Richard, Johan; Scarlata, Claudia; Hathi, Nimish +10 more
We present a rest-UV-selected sample of 32 lensed galaxies at z ~ 2 observed with joint Keck/LRIS rest-UV and Keck/MOSFIRE rest-optical spectra behind the clusters Abell 1689, MACS J0717, and MACS J1149. The sample pushes towards the faintest UV luminosities observed ($-19 \le {M_{\rm UV}} \le -17$) at this redshift. The fraction of dwarf galaxies…
UV-FIR SED modelling of AGNs in IR-luminous galaxies up to z 2.5: understanding the effects of torus models
Pope, A.; Kirkpatrick, A.; Yun, M. +2 more
UV-FIR spectral energy distribution (SED) modelling is an effective way to disentangle emission between star formation (SF) and active galactic nuclei (AGNs) in galaxies; however, this approach becomes uncertain for composite AGNs/SF galaxies that comprise 50-70 per cent of IR-samples. Cosmic X-ray background (XRB) models require a large fraction …
Searching for magnetic fields in pulsating A-type stars: the discovery of a strong field in the probable δ Sct star HD 340577 and a null result for the γ Dor star HR 8799
Ilyin, I.; Hubrig, S.; Schöller, M. +2 more
Numerous δ Sct and γ Dor pulsators are identified in the region of the Hertzsprung-Russell diagram that is occupied by chemically peculiar magnetic Ap stars. The connection between δ Sct and γ Dor pulsations and the magnetic field in Ap stars is however not clear: theory suggests for magnetic Ap stars some critical field strengths for pulsation mo…
Spatially resolved properties of the ionized gas in the H II galaxy J084220+115000
Terlevich, E.; Terlevich, R.; Bresolin, F. +20 more
We present a spatially resolved spectroscopic study for the metal poor H II galaxy J084220+115000 using MEGARA Integral Field Unit observations at the Gran Telescopio Canarias. We estimated the gas metallicity using the direct method for oxygen, nitrogen, and helium and found a mean value of 12 + log (O/H) = 8.03 ± 0.06, and integrated electron de…
The redshift evolution of the S0 fraction for z < 1 in COSMOS
Bekki, Kenji; Groves, Brent A.; Cavanagh, Mitchell K.
Lenticular (S0) galaxies are galaxies that exhibit a bulge and disc component, yet lack any clear spiral features. With features considered intermediary between spirals and ellipticals, S0s have been proposed to be a transitional morphology, however their exact origin and nature is still debated. In this work, we study the redshift evolution of th…
Light elements Na and Al in 58 bulge spheroid stars from APOGEE
Schultheis, M.; Minniti, D.; Valentini, M. +23 more
We identified a sample of 58 candidate stars with metallicity [Fe/H] ≲ -0.8 that likely belong to the old bulge spheroid stellar population, and analyse their Na and Al abundances from Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra. In a previous work, we inspected APOGEE-Stellar Parameter and Chemical Abundance Pipeline a…
An HST survey of 33 T8 to Y1 brown dwarfs: NIR photometry and multiplicity of the coldest isolated objects
Anderson, Jay; Bedin, Luigi R.; Allers, Katelyn +5 more
We present results from a Hubble Space Telescope imaging search for low-mass binary and planetary companions to 33 nearby brown dwarfs with spectral types of T8-Y1. Our survey provides new photometric information for these faint systems, from which we obtained model-derived luminosities, masses, and temperatures. Despite achieving a deep sensitivi…
The Gaia view of the Cepheus OB2 association
Ábrahám, Péter; Kun, Mária; Szilágyi, Máté +1 more
OB associations, birthplaces of the most luminous stars, are key objects for understanding the formation of high-mass stars and their effects on their environments. The aim of this work is to explore the structure and kinematics of the Cepheus OB2 association and characterize the history of star formation in the region - in particular, the role of…
A Search for Unbound Stellar Companions to Pulsar J1124-5916
Kochanek, C. S.
We searched for and found no higher mass (${\gtrsim}3{\rm M}_\odot$) unbound binary stellar companions to the progenitor of pulsar J1124-5916. There are lower mass candidates, but they all have high probabilities of being false positives. There are no candidates for it now being a fully unbound triple system. Even if one of the lower mass candidat…
The connection between stellar mass, age, and quenching time-scale in massive quiescent galaxies at z ≃ 1
Cullen, F.; McLure, R. J.; Dunlop, J. S. +6 more
We present a spectrophotometric study of a mass-complete sample of quiescent galaxies at 1.0 < z < 1.3 with $\mathrm{log_{10}}(M_{\star }/\mathrm{{\rm M}_{\odot }}) \ge 10.3$ drawn from the VANDELS survey, exploring the relationship between stellar mass, age, and star-formation history. Within our sample of 114 galaxies, we derive a stellar-…