Search Publications
Fragmentation Kinematics in Comet 332P/Ikeya-Murakami
Mutchler, Max; Jewitt, David; Weryk, Robert +9 more
We present initial time-resolved observations of the split comet 332P/Ikeya-Murakami taken using the Hubble Space Telescope. Our images reveal a dust-bathed cluster of fragments receding from their parent nucleus at projected speeds in the range 0.06-3.5 m s-1 from which we estimate ejection times from 2015 October to December. The numb…
Pulsation-triggered Mass Loss from AGB Stars: The 60 Day Critical Period
Zijlstra, A. A.; McDonald, I.
Low- and intermediate-mass stars eject much of their mass during the late, red giant branch (RGB) phase of evolution. The physics of their strong stellar winds is still poorly understood. In the standard model, stellar pulsations extend the atmosphere, allowing a wind to be driven through radiation pressure on condensing dust particles. Here, we i…
Observations of Magnetic Flux-rope Oscillation during the Precursor Phase of a Solar Eruption
Zhang, J.; Wang, J. X.; Zhou, G. P.
Based on combined observations from the Interface Region Imaging Spectrograph (IRIS) spectrometer with the coronal emission line of Fe xxi at 1354.08 Å and SDO/AIA images in multiple passbands, we report the finding of the precursor activity manifested as the transverse oscillation of a sigmoid, which is likely a pre-existing magnetic flux rope (M…
IDCS J1426.5+3508: The Most Massive Galaxy Cluster at z > 1.5
Eisenhardt, Peter R.; Gonzalez, Anthony H.; Stanford, S. A. +4 more
We present a deep (100 ks) Chandra observation of IDCS J1426.5+3508, a spectroscopically confirmed, infrared-selected galaxy cluster at z = 1.75. This cluster is the most massive galaxy cluster currently known at z > 1.5, based on existing Sunyaev-Zel’dovich (SZ) and gravitational lensing detections. We confirm this high mass via a variety of X…
A Normal Supermassive Black Hole in NGC 1277
Marconi, Alessandro; Graham, Alister W.; Scott, Nicholas +5 more
The identification of galaxies with “overly massive” black holes requires two measurements: a black hole mass (Mbh) and a host spheroid mass ({M}{{sph,\ast }}). Here we provide our measurements for NGC 1277. Our structural decomposition reveals that NGC 1277 is dominated by a “classical” spheroid with a Sérsic index n = 5.3, …
The Intermediate Luminosity Optical Transient SN 2010da: The Progenitor, Eruption, and Aftermath of a Peculiar Supergiant High-mass X-Ray Binary
Berger, E.; Brown, P. J.; Chornock, R. +7 more
We present optical spectroscopy, ultraviolet-to-infrared imaging, and X-ray observations of the intermediate luminosity optical transient (ILOT) SN 2010da in NGC 300 (d = 1.86 Mpc) spanning from -6 to +6 years relative to the time of outburst in 2010. Based on the light-curve and multi-epoch spectral energy distributions of SN 2010da, we conclude …
Magnetic Field in Atypical Prominence Structures: Bubble, Tornado, and Eruption
Schmieder, B.; Labrosse, N.; Dalmasse, K. +3 more
Spectropolarimetric observations of prominences have been obtained with the THEMIS telescope during four years of coordinated campaigns. Our aim is now to understand the conditions of the cool plasma and magnetism in “atypical” prominences, namely when the measured inclination of the magnetic field departs, to some extent, from the predominantly h…
Ages of Massive Galaxies at 0.5 > z > 2.0 from 3D-HST Rest-frame Optical Spectroscopy
Franx, Marijn; Labbé, Ivo; van Dokkum, Pieter +10 more
We present low-resolution near-infrared stacked spectra from the 3D-HST survey up to z = 2.0 and fit them with commonly used stellar population synthesis models: BC03, FSPS10 (Flexible Stellar Population Synthesis), and FSPS-C3K. The accuracy of the grism redshifts allows the unambiguous detection of many emission and absorption features and thus …
Transition-region/Coronal Signatures and Magnetic Setting of Sunspot Penumbral Jets: Hinode (SOT/FG), Hi-C, and SDO/AIA Observations
Tiwari, Sanjiv K.; Winebarger, Amy R.; Moore, Ronald L. +1 more
Penumbral microjets (PJs) are transient narrow bright features in the chromosphere of sunspot penumbrae, first characterized by Katsukawa et al. using the Ca II H-line filter on Hinode's Solar Optical Telescope (SOT). It was proposed that the PJs form as a result of reconnection between two magnetic components of penumbrae (spines and interspines)…
ASASSN-15lh: A Superluminous Ultraviolet Rebrightening Observed by Swift and Hubble
Baade, Dietrich; Wang, Lifan; Wheeler, J. Craig +9 more
We present and discuss ultraviolet and optical photometry from the Ultraviolet/Optical Telescope, X-ray limits from the X-Ray Telescope on Swift, and imaging polarimetry and ultraviolet/optical spectroscopy with the Hubble Space Telescope, all from observations of ASASSN-15lh. It has been classified as a hydrogen-poor superluminous supernova (SLSN…