Search Publications
The Carnegie Chicago Hubble Program. VI. Tip of the Red Giant Branch Distances to M66 and M96 of the Leo I Group
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +8 more
We determine the distances to the Type Ia supernova host galaxies M66 (NGC 3627) and M96 (NGC 3368) of the Leo I Group using the Tip of the Red Giant Branch (TRGB) method. We target the stellar halos of these galaxies using the Hubble Space Telescope ACS/WFC in the F606W and F814W bandpasses. By pointing to the stellar halos we sample RGB stars pr…
Constraining the Dark-matter Halo Mass of Isolated Low-surface-brightness Galaxies
Bogdán, Ákos; Canning, Rebecca E. A.; Kovács, Orsolya E.
Recent advancements in the imaging of low-surface-brightness objects revealed numerous ultra-diffuse galaxies in the local universe. These peculiar objects are unusually extended and faint: their effective radii are comparable to the Milky Way, but their surface brightnesses are lower than that of dwarf galaxies. Their ambiguous properties motivat…
Investigating the Covering Fraction Distribution of Swift/BAT AGNs with X-Ray and Infrared Observations
Ricci, Claudio; Goulding, Andy D.; Bauer, Franz E. +13 more
We present an analysis of a sample of 69 local obscured Swift/Burst Alert Telescope active galactic nuclei (AGNs) with X-ray spectra from NuSTAR and infrared (IR) spectral energy distributions from Herschel and WISE. We combine this X-ray and IR phenomenological modeling and find a significant correlation between reflected hard X-ray emission and …
The Impact of Turbulent Solar Wind Fluctuations on Solar Orbiter Plasma Proton Measurements
Owen, C. J.; Nicolaou, G.; Verscharen, D. +1 more
Solar Orbiter will observe the Sun and the inner heliosphere to study the connections between solar activity, coronal structure, and the origin of the solar wind. The plasma instruments on board Solar Orbiter will determine the three-dimensional velocity distribution functions of the plasma ions and electrons with high time resolution. The analysi…
Evidence for Asymmetry in the Velocity Distribution of the Interstellar Neutral Helium Flow Observed by IBEX and Ulysses
Wood, Brian E.; Müller, Hans-Reinhard; Möbius, Eberhard
We use observations from the Interstellar Boundary Explorer (IBEX) and Ulysses to explore the possibility that the interstellar neutral helium flowing through the inner solar system possesses an intrinsic non-Maxwellian velocity distribution. In fitting the IBEX and Ulysses data, we experiment with both a kappa distribution and a bi-Maxwellian, in…
Subkiloparsec Imaging of Lyα Emission in a Low-mass, Highly Ionized, Gravitationally Lensed Galaxy at z = 1.84
Pettini, Max; Erb, Dawn K.; Brammer, Gabriel +3 more
Low-mass, low-metallicity galaxies at low to moderate (z ≲ 3) redshifts offer the best opportunity for detailed examination of the interplay between massive stars, ionizing radiation and gas in sources similar to those that likely reionized the universe. We present new narrowband Hubble Space Telescope observations of {Ly}α emission and the adjace…
HST Resolves Stars in a Tiny Body Falling on the Dwarf Galaxy DDO 68
Cignoni, M.; Tosi, M.; Calzetti, D. +9 more
We present new Hubble Space Telescope imaging of a stream-like system associated with the dwarf galaxy DDO 68, located in the Lynx-Cancer void at a distance of D ∼ 12.65 Mpc from us. The stream, previously identified in deep Large Binocular Telescope images as a diffuse low surface brightness structure, is resolved into individual stars in the F60…
Signatures of Magnetic Reconnection at the Footpoints of Fan-shaped Jets on a Light Bridge Driven by Photospheric Convective Motions
Cao, Wenda; Nóbrega-Siverio, Daniel; Li, Dong +5 more
Dynamical jets are generally found on light bridges (LBs), which are key to studying sunspot decay. So far, their formation mechanism is not fully understood. In this paper, we used state-of-the-art observations from the Goode Solar Telescope, the Interface Region Imaging Spectrograph, the Spectro-polarimeter on board Hinode, and the Atmospheric I…
Suprathermal Ion Backgrounds of Solar Energetic Particle Events
Kahler, S. W.; Ling, A. G.
Gradual solar energetic particle (SEP) events result from the acceleration of low-energy suprathermal seed particles to high (E > 10 MeV nuc-1) energies by shocks driven by coronal mass ejections (CMEs). Several studies suggest connections between suprathermal particles measured in situ at 1 au and the seed particles accelerated near…
A Long-duration Luminous Type IIn Supernova KISS15s: Strong Recombination Lines from the Inhomogeneous Ejecta-CSM Interaction Region and Hot Dust Emission from Newly Formed Dust
Tominaga, Nozomu; Yoachim, Peter; Ivezić, Željko +7 more
We report the discovery of an SN 1988Z-like type IIn supernova KISS15s found in a low-mass star-forming galaxy at redshift z = 0.038 during the course of the Kiso Supernova Survey (KISS). KISS15s shows long-duration optical continuum and emission line light curves, indicating that KISS15s is powered by a continuous interaction between the expandin…