Search Publications
Can decaying particle explain cosmic infrared background excess?
Kohri, Kazunori; Nakayama, Kazunori; Moroi, Takeo
Recently the CIBER experiment measured the diffuse cosmic infrared background (CIB) flux and claimed an excess compared with integrated emission from galaxies. We show that the CIB spectrum can be fitted by the additional photons produced by the decay of a new particle. However, it also contributes too much to the anisotropy of the CIB, which is i…
SPIRITS 15c and SPIRITS 14buu: Two Obscured Supernovae in the Nearby Star-forming Galaxy IC 2163
Tinyanont, Samaporn; Smith, Nathan; Gehrz, Robert D. +22 more
SPitzer InfraRed Intensive Transients Survey—SPIRITS—is an ongoing survey of nearby galaxies searching for infrared (IR) transients with Spitzer/IRAC. We present the discovery and follow-up observations of one of our most luminous (M [4.5] = -17.1 ± 0.4 mag, Vega) and reddest ([3.6] - [4.5] = 3.0 ± 0.2 mag) transients, SPIRITS 15c. The …
Electron heating and energy inventory during asymmetric reconnection in a laboratory plasma
Roytershteyn, V.; Chen, Li-Jen; Ji, Hantao +6 more
Electron heating and the energy inventory during asymmetric reconnection are studied in the laboratory plasma with a density ratio of about 8 across the current sheet. Features of asymmetric reconnection such as the large density gradients near the low-density side separatrices, asymmetric in-plane electric field, and bipolar out-of-plane magnetic…
Solar Energetic Particle Forecasting Algorithms and Associated False Alarms
Dalla, S.; Walsh, R. W.; Swalwell, B.
Solar energetic particle (SEP) events are known to occur following solar flares and coronal mass ejections (CMEs). However, some high-energy solar events do not result in SEPs being detected at Earth, and it is these types of event which may be termed "false alarms".
The KMOS Cluster Survey (KCS). III. Fundamental Plane of Cluster Galaxies at z ≃ 1.80 in JKCS 041
Bender, Ralf; Mendel, J. Trevor; Cappellari, Michele +12 more
We present data for 16 galaxies in the overdensity JKCS 041 at z≃ 1.80 as part of the K-band Multi-Object Spectrograph (KMOS) Cluster Survey (KCS). With 20 hr integrations, we have obtained deep absorption-line spectra from which we derived velocity dispersions for seven quiescent galaxies. We combined photometric parameters derived from Hubble Sp…
HD 202206: A Circumbinary Brown Dwarf System
Harrison, Thomas E.; Benedict, G. Fritz
Using Hubble Space Telescope Fine Guidance Sensor astrometry and previously published radial velocity measures, we explore the exoplanetary system HD 202206. Our modeling results in a parallax, {π }{abs}=21.96+/- 0.12 milliseconds of arc, a mass for HD 202206 B of {{ M }}B={0.089}-0.006+0.007 {{ M }}
Improving Empirical Magnetic Field Models by Fitting to In Situ Data Using an Optimized Parameter Approach
Brito, Thiago V.; Morley, Steven K.
A method for comparing and optimizing the accuracy of empirical magnetic field models using in situ magnetic field measurements is presented. The optimization method minimizes a cost function—τ—that explicitly includes both a magnitude and an angular term. A time span of 21 days, including periods of mild and intense geomagnetic activity, was used…
First Weak-lensing Results from “See Change”: Quantifying Dark Matter in the Two z ≳ 1.5 High-redshift Galaxy Clusters SPT-CL J2040-4451 and IDCS J1426+3508
Eisenhardt, Peter; Brodwin, Mark; Perlmutter, Saul +4 more
We present a weak-lensing study of SPT-CL J2040-4451 and IDCS J1426+3508 at z = 1.48 and 1.75, respectively. The two clusters were observed in our “See Change” program, a Hubble Space Telescope survey of 12 massive high-redshift clusters aimed at high-z supernova measurements and weak-lensing estimation of accurate cluster masses. We detect weak b…
From the core to the outskirts: structure analysis of three massive galaxy clusters
Böhringer, H.; Chon, G.; Foëx, G.
Aims: The hierarchical model of structure formation is a key prediction of the Λ cold dark matter model, which can be tested by studying the large-scale environment and the substructure content of massive galaxy clusters. We present here a detailed analysis of the clusters RXC J0225.9-4154, RXC J0528.9-3927, and RXC J2308.3-0211, as part of a…
Optical properties of cometary particles collected by the COSIMA mass spectrometer on-board Rosetta during the rendezvous phase around comet 67P/Churyumov-Gerasimenko
Langevin, Y.; Schulz, R.; Hilchenbach, M. +7 more
40 000 collected cometary particles have been identified on the 21 targets exposed by the COSIMA experiment on-board Rosetta to the environment of comet 67P/Churyumov-Gerasimenko from 2014 August to 2016 September. The images of the targets where obtained by the COSIMA microscope (Cosiscope, 13.95 µm pixel-1) with near grazing inc…