Search Publications
Absolute Calibration of Cepheid Period-Luminosity Relations in NGC 4258
Casertano, Stefano; Filippenko, Alexei V.; Riess, Adam G. +6 more
Owing to its accurate distance measured from water-maser motions, NGC 4258 is one of the most important anchors for calibrating the Cepheid period-luminosity relations (PLRs). We expand on previous efforts and carry out a new Cepheid search in this system using the Hubble Space Telescope. We discover and measure a sample of 669 Cepheids in four ne…
Multi-spacecraft Observations of the Evolution of Interplanetary Coronal Mass Ejections between 0.3 and 2.2 au: Conjunctions with the Juno Spacecraft
Lugaz, Noé; Scolini, Camilla; Winslow, Réka M. +4 more
We present a catalog of 35 interplanetary coronal mass ejections (ICMEs) observed by the Juno spacecraft and at least one other spacecraft during its cruise phase to Jupiter. We identify events observed by MESSENGER, Venus Express, Wind, and STEREO with magnetic features that can be matched unambiguously with those observed by Juno. A multi-spacec…
Ensemble Simulations of the 2012 July 12 Coronal Mass Ejection with the Constant-turn Flux Rope Model
Pogorelov, Nikolai V.; Arge, Charles N.; Singh, Talwinder +1 more
Flux-rope-based magnetohydrodynamic modeling of coronal mass ejections (CMEs) is a promising tool for prediction of the CME arrival time and magnetic field at Earth. In this work, we introduce a constant-turn flux rope model and use it to simulate the 2012 July 12 16:48 CME in the inner heliosphere. We constrain the initial parameters of this CME …
HyGAL: Characterizing the Galactic Interstellar Medium with Observations of Hydrides and Other Small Molecules. I. Survey Description and a First Look Toward W3(OH), W3 IRS5, and NGC 7538 IRS1
Menten, K. M.; Falgarone, E.; Godard, B. +23 more
The HyGAL Stratospheric Observatory for Infrared Astronomy legacy program surveys six hydride molecules-ArH+, OH+, H2O+, SH, OH, and CH-and two atomic constituents-C+ and O-within the diffuse interstellar medium (ISM) by means of absorption-line spectroscopy toward 25 bright Galactic backgroun…
Another Look at Erupting Minifilaments at the Base of Solar X-Ray Polar Coronal "Standard" and "Blowout" Jets
Panesar, Navdeep K.; Moore, Ronald L.; Sterling, Alphonse C.
We examine 21 solar polar coronal jets that we identify in soft X-ray images obtained from the Hinode/X-ray telescope (XRT). We identify 11 of these as blowout jets and four as standard jets (with six uncertain), based on their X-ray-spire widths being respectively wide or narrow (compared to the jet's base) in the XRT images. From corresponding e…
Magnetic Field Intermittency in the Solar Wind: Parker Solar Probe and SolO Observations Ranging from the Alfvén Region up to 1 AU
Fedorov, A.; Louarn, P.; Velli, Marco +19 more
Parker Solar Probe (PSP) and SolO data are utilized to investigate magnetic field intermittency in the solar wind (SW). Small-scale intermittency (20-100 d i ) is observed to radially strengthen when methods relying on higher-order moments are considered (SF q ; SDK), but no clear trend is observed at larger scales. However,…
Supernova Remnants in M83 as Observed with MUSE
Della Bruna, Lorenza; Blair, William P.; Adamo, Angela +4 more
Here we describe a new study of the supernova remnants (SNRs) and SNR candidates in nearby face-on spiral galaxy M83, based primarily on MUSE integral field spectroscopy. Our revised catalog of SNR candidates in M83 has 366 objects, 81 of which are reported here for the first time. Of these, 229 lie within the MUSE observation region, 160 of which…
The Candidate Progenitor Companion Star of the Type Ib/c SN 2013ge
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Williams, Benjamin F. +17 more
This Letter presents the detection of a source at the position of the Type Ib/c supernova (SN) 2013ge more than four years after the radioactive component is expected to have faded. This source could mark the first post-SN direct detection of a surviving companion to a stripped-envelope Type Ib/c explosion. We test this hypothesis and find the sha…
Magellan/IMACS Spectroscopy of Grus I: A Low Metallicity Ultra-faint Dwarf Galaxy
Li, Ting S.; Frebel, Anna; Simon, Joshua D. +3 more
We present a chemodynamical study of the Grus I ultra-faint dwarf galaxy (UFD) from medium-resolution (R ~ 11,000) Magellan/IMACS spectra of its individual member stars. We identify eight confirmed members of Grus I, based on their low metallicities and coherent radial velocities, and four candidate members for which only velocities are derived. I…
Evolution of X-Ray Activity in <25 Myr Old Pre-main Sequence Stars
Garmire, Gordon P.; Feigelson, Eric D.; Broos, Patrick S. +4 more
Measuring the evolution of X-ray emission from pre-main-sequence (PMS) stars gives insight into two issues: the response of magnetic dynamo processes to changes in the interior structure, and the effects of high-energy radiation on protoplanetary disks and primordial planetary atmospheres. We present a sample of 6003 stars with ages 7-25 Myr in 10…