Search Publications
INTEGRAL Upper Limits on Gamma-Ray Emission Associated with the Gravitational Wave Event GW150914
Hanlon, L.; Mereghetti, S.; von Kienlin, A. +14 more
Using observations of the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), we place upper limits on the gamma-ray and hard X-ray prompt emission associated with the gravitational wave event GW150914, which was discovered by the LIGO/Virgo Collaboration. The omnidirectional view of the INTEGRAL/SPI-ACS has allowed us to constrain the fra…
Are IRIS Bombs Connected to Ellerman Bombs?
He, Jiansen; Tian, Hui; Xu, Zhi +1 more
Recent observations by the Interface Region Imaging Spectrograph (IRIS) have revealed pockets of hot gas (∼2-8 × 104 K) potentially resulting from magnetic reconnection in the partially ionized lower solar atmosphere (IRIS bombs; IBs). Using joint observations between IRIS and the Chinese New Vacuum Solar Telescope, we have identified 1…
Do the Most Massive Black Holes at z = 2 Grow via Major Mergers?
Jahnke, K.; Silverman, J. D.; Schulze, A. +11 more
The most frequently proposed model for the origin of quasars holds that the high accretion rates seen in luminous active galactic nuclei (AGN) are primarily triggered during major mergers between gas-rich galaxies. While plausible for decades, this model has only begun to be tested with statistical rigor in the past few years. Here, we report on a…
M31N 2008-12a - The Remarkable Recurrent Nova in M31: Panchromatic Observations of the 2015 Eruption.
Ness, J. -U.; Boumis, P.; Henze, M. +52 more
The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption 10 times, including yearly eruptions from 2008 to 2014. With a measured recurrence period of {P}{rec}=351+/- 13 days (we believe the true value to be half of this) and a white dwarf very close to the Chandrasekhar limit, M31N 2008-12a has become the leading …
The Story of Supernova “Refsdal” Told by Muse
Treu, T.; Grillo, C.; Balestra, I. +10 more
We present Multi Unit Spectroscopic Explorer (MUSE) observations in the core of the Hubble Frontier Fields (HFF) galaxy cluster MACS J1149.5+2223, where the first magnified and spatially resolved multiple images of supernova (SN) “Refsdal” at redshift 1.489 were detected. Thanks to a Director's Discretionary Time program with the Very Large Telesc…
Spatially Resolved Dust Maps from Balmer Decrements in Galaxies at z ~ 1.4
van Dokkum, Pieter G.; Franx, Marijn; Whitaker, Katherine E. +6 more
We derive average radial gradients in the dust attenuation toward H II regions in 609 galaxies at z ∼ 1.4, using measurements of the Balmer decrement out to r ∼ 3 kpc. The Balmer decrements are derived from spatially resolved maps of Hα and Hβ emission from the 3D-HST survey. We find that with increasing stellar mass M both the normalization and s…
The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Molecular Gas Reservoirs in High-redshift Galaxies
Carilli, Chris; Bell, Eric F.; Bacon, Roland +29 more
We study the molecular gas properties of high-z galaxies observed in the ALMA Spectroscopic Survey (ASPECS) that targets an ∼1 arcmin2 region in the Hubble Ultra Deep Field (UDF), a blind survey of CO emission (tracing molecular gas) in the 3 and 1 mm bands. Of a total of 1302 galaxies in the field, 56 have spectroscopic redshifts and c…
VLT FORS2 Comparative Transmission Spectroscopy: Detection of Na in the Atmosphere of WASP-39b from the Ground
Nikolov, Nikolay; Fortney, Jonathan J.; Gibson, Neale P. +5 more
We present transmission spectroscopy of the warm Saturn-mass exoplanet WASP-39b made with the Very Large Telescope FOcal Reducer and Spectrograph (FORS2) across the wavelength range 411-810 nm. The transit depth is measured with a typical precision of 240 parts per million (ppm) in wavelength bins of 10 nm on a V = 12.1 mag star. We detect the sod…
Inferred H⍺ Flux as a Star Formation Rate Indicator at z ~ 4-5: Implications for Dust Properties, Burstiness, and the z = 4-8 Star Formation Rate Functions
Wilkins, Stephen M.; Franx, Marijn; Labbé, Ivo +3 more
We derive Hα fluxes for a large spectroscopic and photometric-redshift-selected sample of sources over GOODS-North and South in the redshift range z = 3.8-5.0 with deep Hubble Space Telescope (HST), Spitzer/IRAC, and ground-based observations. The Hα flux is inferred based on the offset between the IRAC 3.6 µm flux and that predicted from th…
Green Pea Galaxies Reveal Secrets of Lyα Escape
Jaskot, Anne; Malhotra, Sangeeta; Gronke, Max +5 more
We analyze archival Lyα spectra of 12 “Green Pea” galaxies observed with the Hubble Space Telescope, model their Lyα profiles with radiative transfer models, and explore the dependence of the Lyα escape fraction on various properties. Green Pea galaxies are nearby compact starburst galaxies with [O III] λ5007 equivalent widths (EWs) of hundreds of…