Search Publications
First Phase Space Portrait of a Hierarchical Stellar Structure in the Milky Way
Dalessandro, Emanuele; Saracino, S.; Bellazzini, M. +10 more
We present the first detailed observational picture of a possible ongoing massive cluster hierarchical assembly in the Galactic disk as revealed by the analysis of the stellar full phase space (3D positions and kinematics and spectro-photometric properties) of an extended area (6° diameter) surrounding the well-known h and χ Persei double stellar …
The M-dwarf Ultraviolet Spectroscopic Sample. I. Determining Stellar Parameters for Field Stars
France, Kevin; Youngblood, Allison; Pineda, J. Sebastian
Accurate stellar properties are essential for precise stellar astrophysics and exoplanetary science. In the M-dwarf regime, much effort has gone into defining empirical relations that can use readily accessible observables to assess physical stellar properties. Often, these relations for the quantity of interest are cast as a nonlinear function of…
Understanding Polarized Dust Emission from ρ Ophiuchi A in Light of Grain Alignment and Disruption by Radiative Torques
Soam, Archana; Hoang, Thiem; Lee, Hyeseung +5 more
The alignment of dust grains with the ambient magnetic field produces polarization of starlight as well as thermal dust emission. Using the archival SOFIA/HAWC+ polarimetric data observed toward the ρ Ophiuchus (Oph) A cloud hosted by a B star at 89 and 154 µm, we find that the fractional polarization of thermal dust emission first increases…
Time and Charge-sign Dependence of the Heliospheric Modulation of Cosmic Rays
Potgieter, M. S.; Aslam, O. P. M.; Bisschoff, D. +4 more
Simultaneous and continuous observations of galactic cosmic-ray electrons (e-) and positrons (e+) from the PAMELA and AMS02 space experiments are most suitable for numerical modeling studies of the heliospheric modulation of these particles below 50 GeV. A well-established comprehensive three-dimensional modulation model is a…
The Source of Leaking Ionizing Photons from Haro11: Clues from HST/COS Spectroscopy of Knots A, B, and C
Cannon, John M.; Hayes, Matthew; Östlin, Göran +15 more
Understanding the escape of ionizing (Lyman continuum) photons from galaxies is vital for determining how galaxies contributed to reionization in the early universe. While directly detecting the Lyman continuum from high-redshift galaxies is impossible due to the intergalactic medium, low-redshift galaxies in principle offer this possibility but r…
Circumstellar Medium Constraints on the Environment of Two Nearby Type Ia Supernovae: SN 2017cbv and SN 2020nlb
Swift, Jonathan J.; Galbany, L.; Brown, P. J. +24 more
We present deep Chandra X-ray observations of two nearby Type Ia supernovae, SN 2017cbv and SN 2020nlb, which reveal no X-ray emission down to a luminosity LX ≲ 5.3 × 1037 and ≲ 5.4 × 1037 erg s-1 (0.3-10 keV), respectively, at ~16-18 days after the explosion. With these limits, we constrain the pre-expl…
Discovery of a Radio Halo (and Relic) in a M500<2×1014 M⊙ Cluster
Di Gennaro, G.; Brunetti, G.; Rossetti, M. +12 more
Radio halos are diffuse synchrotron sources observed in dynamically unrelaxed galaxy clusters. Current observations and models suggest that halos trace turbulent regions in the intracluster medium where mildly relativistic particles are reaccelerated during cluster mergers. Due to the higher luminosities and detection rates with increasing cluster…
Investigating the Nature of MGRO J1908+06 with Multiwavelength Observations
Torres, Diego F.; Li, Jian; Kerr, Matthew +7 more
The unidentified TeV source MGRO J1908+06, with emission extending from hundreds of GeV to beyond 100 TeV, is one of the most intriguing sources in the Galactic plane. MGRO J1908+06 spatially associates with an IceCube hotspot of neutrino emission. Although the hotspot is not significant yet, this suggests a possible hadronic origin of the observe…
Optical Analysis and Modeling of HD96670, a New Black Hole X-Ray Binary Candidate
Gomez, Sebastian; Grindlay, Jonathan E.
We report on optical observations and modeling of HD96670, a single-line spectroscopic binary in the Carina OB2 association. We collected 10 epochs of optical spectroscopy, and optical photometry on 17 nonconsecutive nights on the source. We construct a radial velocity curve from the spectra, and update the orbital period of the binary to be P = 5…
The Relativistic Jet Orientation and Host Galaxy of the Peculiar Blazar PKS 1413+135
Lähteenmäki, A.; Pearson, T. J.; Vedantham, H. K. +26 more
PKS 1413+135 is one of the most peculiar blazars known. Its strange properties led to the hypothesis almost four decades ago that it is gravitationally lensed by a mass concentration associated with an intervening galaxy. It exhibits symmetric achromatic variability, a rare form of variability that has been attributed to gravitational milli-lensin…