Search Publications
MUSE Spectroscopic Identifications of Ultra-faint Emission Line Galaxies with M UV ∼ -15
Bacon, Roland; Bouché, Nicolas; Inami, Hanae +16 more
Using an ultra-deep blind survey with the MUSE integral field spectrograph on the European Southern Observatory Very Large Telescope, we obtain spectroscopic redshifts to a depth never before explored: galaxies with observed magnitudes m AB ≳ 30-32. Specifically, we detect objects via Lyα emission at 2.9 < z < 6.7 without individu…
ALMA Resolves C I Emission from the β Pictoris Debris Disk
Roberge, Aki; Pantin, Eric; Cataldi, Gianni +8 more
The debris disk around β Pictoris is known to contain gas. Previous ALMA observations revealed a CO belt at ∼85 au with a distinct clump, interpreted as a location of enhanced gas production. Photodissociation converts CO into C and O within ∼50 a. We resolve C I emission at 492 GHz using ALMA and study its spatial distribution. C I shows the same…
A Geometrical 1% Distance to the Short-period Binary Cepheid V1334 Cygni
Nelan, E.; Mowlavi, N.; Eyer, L. +18 more
Cepheid stars play a considerable role as extragalactic distances indicators, thanks to the simple empirical relation between their pulsation period and their luminosity. They overlap with that of secondary distance indicators, such as Type Ia supernovae, whose distance scale is tied to Cepheid luminosities. However, the period-luminosity (P-L) re…
An Ultra Metal-poor Star Near the Hydrogen-burning Limit
Casey, Andrew R.; Thompson, Ian B.; Schlaufman, Kevin C.
It is unknown whether or not low-mass stars can form at low metallicity. While theoretical simulations of Population III (Pop III) star formation show that protostellar disks can fragment, it is impossible for those simulations to discern if those fragments survive as low-mass stars. We report the discovery of a low-mass star on a circular orbit w…
Multi-episode Chromospheric Evaporation Observed in a Solar Flare
Tian, H.; Chen, N. -H.
With observations of the Interface Region Imaging Spectrograph (IRIS), we study chromospheric heating and evaporation during an M1.6 flare SOL2015-03-12T11:50. At the flare ribbons, the Mg II 2791.59 Å line shows quasi-periodic short-duration red-wing enhancement, which is likely related to repetitive chromospheric condensation as a result of epis…
A New Probe of Line-of-sight Magnetic Field Tangling
Clark, S. E.
The Galactic neutral hydrogen (H I ) sky at high Galactic latitudes is suffused with linear structure. Particularly prominent in narrow spectral intervals, these linear H I features are well aligned with the plane-of-sky magnetic field orientation as measured with optical starlight polarization and polarized thermal dust emission. We analyze the c…
Constraints for the Progenitor Masses of Historic Core-collapse Supernovae
Dolphin, Andrew E.; Williams, Benjamin F.; Dalcanton, Julianne J. +3 more
We age-date the stellar populations associated with 12 historic nearby core-collapse supernovae (CCSNe) and two supernova impostors; from these ages, we infer their initial masses and associated uncertainties. To do this, we have obtained new Hubble Space Telescope imaging covering these CCSNe. Using these images, we measure resolved stellar photo…
On Cepheid Distance Scale Bias Due to Stellar Companions and Cluster Populations
Riess, Adam G.; Anderson, Richard I.
State-of-the-art photometric measurements of extragalactic Cepheids account for the mean additional light due to chance superposition of Cepheids on crowded backgrounds through the use of artificial star measurements. However, light from stars physically associated with Cepheids may bias relative distance measurements if the changing spatial resol…
The Molecular Gas Content and Fuel Efficiency of Starbursts at z ∼ 1.6 with ALMA
Daddi, E.; Rodighiero, G.; Béthermin, M. +17 more
We present an analysis of the molecular gas properties, based on CO (2-1) emission, of 12 starburst galaxies at z ∼ 1.6 selected by having a boost (≳4×) in their star formation rate (SFR) above the average star-forming galaxy at an equivalent stellar mass. ALMA observations are acquired of six more galaxies than previously reported through our eff…
ALMA Detection of Extended Millimeter Halos in the HD 32297 and HD 61005 Debris Disks
MacGregor, Meredith A.; Weinberger, Alycia J.; Hughes, A. Meredith +7 more
We present Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm (230 GHz) observations of the HD 32297 and HD 61005 debris disks, two of the most iconic debris disks because of their dramatic swept-back wings seen in scattered light images. These observations achieve sensitivities of 14 and 13 µJy beam-1 for HD 32297 and HD …