Search Publications
Deconstructing Thermal Sunyaev-Zel’dovich - Gravitational Lensing Cross-correlations: Implications for the Intracluster Medium
Battaglia, N.; Hill, J. C.; Murray, N.
Recent first detections of the cross-correlation of the thermal Sunyaev-Zel’dovich (tSZ) signal in Planck cosmic microwave background (CMB) temperature maps with gravitational lensing maps inferred from the Planck CMB data and the CFHTLenS galaxy survey provide new probes of the relationship between baryons and dark matter. Using cosmological hydr…
Chemically Distinct Nuclei and Outflowing Shocked Molecular Gas in Arp 220
Sturm, E.; Greve, T. R.; Planesas, P. +9 more
We present the results of interferometric spectral line observations of Arp 220 at 3.5 mm and 1.2 mm from the Plateau de Bure Interferometer, imaging the two nuclear disks in H13CN(1-0) and (3-2), H13CO+(1-0) and (3-2), and HN13C(3-2) as well as SiO(2-1) and (6-5), HC15N(3-2), and SO(66
The Formation of IRIS Diagnostics. VII. The Formation of the OI 135.56 NM Line in the Solar Atmosphere
Carlsson, Mats; Lin, Hsiao-Hsuan
The O i 135.56 nm line is covered by NASA's Interface Region Imaging Spectrograph (IRIS) small explorer mission which studies how the solar atmosphere is energized. We study here the formation and diagnostic potential of this line by means of non-local thermodynamic equilibrium modeling employing both 1D semi-empirical and 3D radiation magnetohydr…
Spatially Resolved Imaging and Spectroscopy of Candidate Dual Active Galactic Nuclei
Shields, G. A.; Medling, A. M.; Comerford, J. M. +2 more
When galaxies merge, both central supermassive black holes are immersed in a dense and chaotic environment. If there is sufficient gas in the nuclear regions, one expects to see close pairs of active galactic nuclei (AGNs), or dual AGNs, in a fraction of galaxy mergers. However, finding them remains a challenge. The presence of double-peaked [O ii…
Radio-quiet and Radio-loud Pulsars: Similar in Gamma-Rays but Different in X-Rays
Marelli, M.; Saz Parkinson, P. M.; Wolff, M. T. +4 more
We present new Chandra and XMM-Newton observations of a sample of eight radio-quiet (RQ) γ-ray pulsars detected by the Fermi Large Area Telescope. For all eight pulsars we identify the X-ray counterpart, based on the X-ray source localization and the best position obtained from γ-ray pulsar timing. For PSR J2030+4415 we found evidence for a ∼10″-l…
Self-Absorption in the Solar Transition Region
He, Jiansen; Tian, Hui; Barczynski, Krzysztof +7 more
Transient brightenings in the transition region of the Sun have been studied for decades and are usually related to magnetic reconnection. Recently, absorption features due to chromospheric lines have been identified in transition region emission lines raising the question of the thermal stratification during such reconnection events. We analyze d…
Dense Gas Fraction and Star-formation Efficiency Variations in the Antennae Galaxies
Bolatto, A. D.; da Cunha, E.; Leroy, A. K. +5 more
We use the Combined Array for Research in Millimeter-wave Astronomy (CARMA) millimeter interferometer to map the Antennae Galaxies (NGC 4038/39), tracing the bulk of the molecular gas via the 12CO(1-0) line and denser molecular gas via the high density transitions HCN(1-0), HCO+(1-0), CS(2-1), and HNC(1-0). We detect bright e…
The Scaling Relations and the Fundamental Plane for Radio Halos and Relics of Galaxy Clusters
Yuan, Z. S.; Han, J. L.; Wen, Z. L.
Diffuse radio emission in galaxy clusters is known to be related to cluster mass and cluster dynamical state. We collect the observed fluxes of radio halos, relics, and mini-halos for a sample of galaxy clusters from the literature, and calculate their radio powers. We then obtain the values of cluster mass or mass proxies from previous observatio…
Transiting the Sun: the Impact of Stellar Activity on X-Ray and Ultraviolet Transits
Llama, J.; Shkolnik, E. L.
Transits of hot Jupiters in X-rays and the ultraviolet have been shown to be both deeper and more variable than the corresponding optical transits. This variability has been attributed to hot Jupiters having extended atmospheres at these wavelengths. Using resolved images of the Sun from NASA’s Solar Dynamics Observatory spanning 3.5 yr of Solar C…
Dusty Starbursts and the Formation of Elliptical Galaxies: A SCUBA-2 Survey of a z = 1.46 Cluster
Thomson, A. P.; Smail, Ian; Swinbank, A. M. +8 more
We report the results of a deep SCUBA-2 850 and 450 µm survey for dust-obscured ultra-/luminous infrared galaxies (U/LIRGs) in the field of the z = 1.46 cluster XCS J2215.9-1738. We detect a striking overdensity of submillimeter sources coincident with the core of this cluster: ∼3-4 × higher than expected in a blank field. We use the likely …