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SN 2022acko: The First Early Far-ultraviolet Spectra of a Type IIP Supernova
Van Dyk, Schuyler D.; Smith, Nathan; Hillier, D. John +41 more
We present five far- and near-ultraviolet spectra of the Type II plateau supernova, SN 2022acko, obtained 5, 6, 7, 19, and 21 days after explosion, all observed with the Hubble Space Telescope/Space Telescope Imaging Spectrograph. The first three epochs are earlier than any Type II plateau supernova has been observed in the far-ultraviolet reveali…
Near-IR Weak-lensing (NIRWL) Measurements in the CANDELS Fields. I. Point-spread Function Modeling and Systematics
Chary, Ranga-Ram; Taylor, Peter; Jee, M. James +5 more
We have undertaken a near-IR weak-lensing (NIRWL) analysis of the CANDELS HST/WFC3-IR F160W observations. With the Gaia proper motion–corrected catalog as an astrometric reference, we updated the astrometry of the five CANDELS mosaics and achieved an absolute alignment within 0.″02 ± 0.″02, on average, which is a factor of several superior to exis…
The Physical Thickness of Stellar Disks to z ∼ 2
Heckman, Timothy M.; Snyder, Gregory F.; Simons, Raymond C. +2 more
In local disk galaxies such as our Milky Way, older stars generally inhabit a thicker disk than their younger counterparts. Two competing models have attempted to explain this result: one in which stars first form in thin disks that gradually thicken with time through dynamical heating, and one in which stars form in thick disks at early times and…
Molecular Mapping of DR Tau's Protoplanetary Disk, Envelope, Outflow, and Large-scale Spiral Arm
Andrews, Sean M.; Bae, Jaehan; Bergin, Edwin A. +2 more
DR Tau has been noted for its unusually high variability in comparison with other T Tauri stars. Although it is one of the most extensively studied pre-main-sequence stars, observations with millimeter interferometry have so far been relatively limited. We present NOEMA images of 12CO, 13CO, C18O, SO, DCO+
HST FUV Spectroscopy of Super Star Cluster A in the Green Pea Analog Mrk 71: Revealing the Presence of Very Massive Stars
Jaskot, Anne E.; Östlin, Göran; Hernandez, Svea +10 more
Mrk 71 is a low-metallicity (Z = 0.16 Z ☉) starburst region in the local dwarf galaxy NGC 2366, hosting two super star clusters (SSCs A and B), and it is recognized as a Green Pea (GP) analog with SSC A responsible for the GP properties. We present STIS and FOS far-ultraviolet (FUV) spectra of the embedded SSC Mrk 71-A obtained with the…
X-Ray and Ultraviolet Emission of the Young Planet-hosting Star V1298 Tau from Coordinated Observations with XMM-Newton and Hubble Space Telescope
Rainer, M.; Sanz-Forcada, J.; D'Orazi, V. +16 more
Atmospheric mass loss plays a major role in the evolution of exoplanets. This process is driven by the stellar high-energy irradiation, especially in the first hundreds of millions of years after dissipation of the proto-planetary disk. A major source of uncertainty in modeling atmospheric photoevaporation and photochemistry is due to the lack of …
Evolution of Nonparametric Morphology of Galaxies in the JWST CEERS Field at z ≃ 0.8-3.0
Fang, Guanwen; Kong, Xu; Chen, Xinkai +3 more
Galaxy morphology is one of the most fundamental ways to describe galaxy properties, but the morphology we observe may be affected by wavelength and spatial resolution, which may introduce systematic bias when comparing galaxies at different redshift. Taking advantage of the broad wavelength coverage from optical to near-IR and the high-resolution…
Isolating Dust and Free-Free Emission in ONC Proplyds with ALMA Band 3 Observations
Fang, Min; Ginsburg, Adam; Bally, John +6 more
The Orion Nebula Cluster (ONC) hosts protoplanetary disks experiencing external photoevaporation by the cluster's intense UV field. These "proplyds" are comprised of a disk surrounded by an ionization front. We present ALMA Band 3 (3.1 mm) continuum observations of 12 proplyds. Thermal emission from the dust disks and free-free emission from the i…
Magnetic Structures and Turbulence in SN 1006 Revealed with Imaging X-Ray Polarimetry
Kaaret, Philip; Wu, Kinwah; Enoto, Teruaki +99 more
Young supernova remnants strongly modify the surrounding magnetic fields, which in turn play an essential role in accelerating cosmic rays (CRs). The X-ray polarization measurements probe magnetic field morphology and turbulence at the immediate acceleration site. We report the X-ray polarization distribution in the northeastern shell of SN 1006 f…
The Metal-weak Milky Way Stellar Disk Hidden in the Gaia-Sausage-Enceladus Debris: The APOGEE DR17 View
Feltzing, Sofia; Feuillet, Diane
We have for the first time identified the early stellar disk in the Milky Way by using a combination of elemental abundances and kinematics. Using data from APOGEE DR17 and Gaia we select stars in the Mg-Mn-Al-Fe plane with elemental abundances indicative of an accreted origin and find stars with both halo-like and disk-like kinematics. The stars …