Search Publications
Fading AGN Candidates: AGN Histories and Outflow Signatures
Schawinski, Kevin; Sartori, Lia F.; Keel, William C. +12 more
We consider the energy budgets and radiative history of eight fading active galactic nuclei (AGNs), identified from an energy shortfall between the requirements to ionize very extended (radius > 10 kpc) ionized clouds and the luminosity of the nucleus as we view it directly. All show evidence of significant fading on timescales of ≈50,000 yr. W…
CANDELS: Elevated Black Hole Growth in the Progenitors of Compact Quiescent Galaxies at z ∼ 2
Barro, Guillermo; Santini, Paola; Giavalisco, Mauro +31 more
We examine the fraction of massive ({M}* > {10}10 {M}⊙ ) compact star-forming galaxies (cSFGs) that host an active galactic nucleus (AGN) at z∼ 2. These cSFGs are likely the direct progenitors of the compact quiescent galaxies observed at this epoch, which are the first population of passive galaxies to appear i…
LOFAR Discovery of the Fastest-spinning Millisecond Pulsar in the Galactic Field
Burnett, T. H.; Camilo, F.; Michelson, P. F. +15 more
We report the discovery of PSR J0952-0607, a 707 Hz binary millisecond pulsar that is now the fastest-spinning neutron star known in the Galactic field (I.e., outside of a globular cluster). PSR J0952-0607 was found using LOFAR at a central observing frequency of 135 MHz, well below the 300 MHz to 3 GHz frequencies typically used in pulsar searche…
Modeling the Anomalous Microwave Emission with Spinning Nanoparticles: No PAHs Required
Draine, B. T.; Hensley, Brandon S.
In light of recent observational results indicating an apparent lack of correlation between the anomalous microwave emission (AME) and mid-infrared emission from polycyclic aromatic hydrocarbons, we assess whether rotational emission from spinning silicate and/or iron nanoparticles could account for the observed AME without violating observational…
The Y-type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry, and Near-infrared Spectroscopy
Luhman, K. L.; Tremblin, P.; Morley, Caroline V. +2 more
The survey of the mid-infrared sky by the Wide-field Infrared Survey Explorer (WISE) led to the discovery of extremely cold, low-mass brown dwarfs, classified as Y dwarfs, which extend the T class to lower temperatures. Twenty-four Y dwarfs are known at the time of writing. Here we present improved parallaxes for four of these, determined using Sp…
X-Ray and Radio Observations of the Magnetar SGR J1935+2154 during Its 2014, 2015, and 2016 Outbursts
Göğüş, Ersin; Kouveliotou, Chryssa; Lin, Lin +10 more
We analyzed broadband X-ray and radio data of the magnetar SGR J1935+2154 taken in the aftermath of its 2014, 2015, and 2016 outbursts. The source soft X-ray spectrum <10 keV is well described with a blackbody+power-law (BB+PL) or 2BB model during all three outbursts. Nuclear Spectroscopic Telescope Array observations revealed a hard X-ray tail…
A Multiple Flux-tube Solar Wind Model
Rouillard, Alexis P.; Pinto, Rui F.
We present a new model, MULTI-VP, which computes the three-dimensional structure of the solar wind and includes the chromosphere, the transition region, and the corona and low heliosphere. MULTI-VP calculates a large ensemble of wind profiles flowing along open magnetic field lines that sample the entire three-dimensional atmosphere or, alternativ…
The Circumstellar Disk HD 169142: Gas, Dust, and Planets Acting in Concert?
Pinte, C.; Ménard, F.; van der Plas, G. +34 more
HD 169142 is an excellent target for investigating signs of planet-disk interaction due to previous evidence of gap structures. We perform J-band (∼1.2 µm) polarized intensity imaging of HD 169142 with VLT/SPHERE. We observe polarized scattered light down to 0.″16 (∼19 au) and find an inner gap with a significantly reduced scattered-light fl…
ALMA Observations of Gas-rich Galaxies in z ∼ 1.6 Galaxy Clusters: Evidence for Higher Gas Fractions in High-density Environments
Cooper, M. C.; van Kampen, E.; Demarco, R. +16 more
We present ALMA CO (2-1) detections in 11 gas-rich cluster galaxies at z ∼ 1.6, constituting the largest sample of molecular gas measurements in z > 1.5 clusters to date. The observations span three galaxy clusters, derived from the Spitzer Adaptation of the Red-sequence Cluster Survey. We augment the >5σ detections of the CO (2-1) fluxes wi…
Hubble Space Telescope Proper Motion (HSTPROMO) Catalogs of Galactic Globular Clusters. V. The Rapid Rotation of 47 Tuc Traced and Modeled in Three Dimensions
Anderson, J.; Piotto, G.; Vesperini, E. +5 more
High-precision proper motions of the globular cluster 47 Tuc have allowed us to measure for the first time the cluster rotation in the plane of the sky and the velocity anisotropy profile from the cluster core out to about 13‧. These profiles are coupled with prior measurements along the line of sight (LOS) and the surface brightness profile and f…