Search Publications
The Physical Environment around IRAS 17599-2148: Infrared Dark Cloud and Bipolar Nebula
Dewangan, L. K.; Ojha, D. K.; Zinchenko, I. +3 more
We present a multiscale and multiwavelength study to investigate the star formation process around IRAS 17599-2148, which is part of an elongated filamentary structure (EFS) (extension ∼21 pc) seen in the Herschel maps. Using the Herschel data analysis, at least six massive clumps (M clump ∼ 777-7024 M ⊙) are found in the EFS…
On the State of a Solar Active Region Before Flares and CMEs
Erdélyi, R.; Korsós, M. B.
Several attempts have been made to find reliable diagnostic tools to determine the state prior to flares and related coronal mass ejections (CMEs) in solar active regions (ARs). Characterization of the level of mixed states is carried out using the Debrecen sunspot Data for 116 flaring ARs. Conditional flare probabilities (CFPs) are calculated for…
The Role of Quenching Time in the Evolution of the Mass-size Relation of Passive Galaxies from the Wisp Survey
Zanella, A.; Scarlata, C.; Malkan, M. +13 more
We analyze how passive galaxies at z ∼ 1.5 populate the mass-size plane as a function of their stellar age, to understand if the observed size growth with time can be explained with the appearance of larger quenched galaxies at lower redshift. We use a sample of 32 passive galaxies extracted from the Wide Field Camera 3 Infrared Spectroscopic Para…
Protoplanetary Disk Shadowing by Gas Infalling onto the Young Star AK Sco
France, Kevin; Gómez de Castro, Ana I.; Loyd, Robert O. P. +2 more
Young solar-type stars grow through the accretion of material from the circumstellar disk during pre-main-sequence (PMS) evolution. The ultraviolet radiation generated in this process plays a key role in the chemistry and evolution of young planetary disks. In particular, the hydrogen Lyα line (Lyα) etches the disk surface by driving photoevaporat…
A VLA Survey for Faint Compact Radio Sources in the Orion Nebula Cluster
Williams, Jonathan P.; Sheehan, Patrick D.; Eisner, Josh A. +1 more
We present Karl G. Jansky Very Large Array 1.3, 3.6, and 6 cm continuum maps of compact radio sources in the Orion Nebular Cluster (ONC). We mosaicked 34 arcmin2 at 1.3 cm, 70 arcmin2 at 3.6 cm and 109 arcmin2 at 6 cm, containing 778 near-infrared detected young stellar objects and 190 Hubble Space Telescope-identi…
A Symmetric Inner Cavity in the HD 141569A Circumstellar Disk
Augereau, J. -C.; Boccaletti, A.; Lagrange, A. -M. +6 more
Some circumstellar disks, called transitional or hybrid disks, present characteristics of both protoplanetary disks (significant amount of gas) and debris disks (evolved structures around young main-sequence stars, composed of second generation dust, from collisions between planetesimals). Therefore, they are ideal astrophysical laboratories to wi…
Herschel/HIFI Spectral Mapping of C+, CH+, and CH in Orion BN/KL: The Prevailing Role of Ultraviolet Irradiation in CH+ Formation
Bergin, Edwin A.; Neufeld, David A.; Ossenkopf-Okada, Volker +8 more
The CH+ ion is a key species in the initial steps of interstellar carbon chemistry. Its formation in diverse environments where it is observed is not well understood, however, because the main production pathway is so endothermic (4280 K) that it is unlikely to proceed at the typical temperatures of molecular clouds. We investigate the …
IDCS J1426.5+3508: Weak Lensing Analysis of a Massive Galaxy Cluster at z = 1.75
Massey, Richard; Rhodes, Jason; Marrone, Daniel P. +7 more
We present a weak lensing study of the galaxy cluster IDCS J1426.5+3508 at z = 1.75, which is the highest-redshift strong lensing cluster known and the most distant cluster for which a weak lensing analysis has been undertaken. Using F160W, F814W, and F606W observations with the Hubble Space Telescope, we detect tangential shear at 2σ significance…
The Magnetic Field of L1544. I. Near-infrared Polarimetry and the Non-uniform Envelope
Tassis, K.; Goldsmith, Paul F.; Clemens, Dan P.
The magnetic field (B-field) of the starless dark cloud L1544 has been studied using near-infrared (NIR) background starlight polarimetry (BSP) and archival data in order to characterize the properties of the plane-of-sky B-field. NIR linear polarization measurements of over 1700 stars were obtained in the H band and 201 of these were also measure…
Chandra and XMM-Newton X-Ray Observations of the Hyperactive T Tauri Star RY Tau
Skinner, Stephen L.; Güdel, Manuel; Audard, Marc
We present results of pointed X-ray observations of the accreting jet-driving T Tauri star RY Tau using Chandra and XMM-Newton. We obtained high-resolution grating spectra and excellent-quality CCD spectra and light curves with the objective of identifying the physical mechanisms underlying RY Tau’s bright X-ray emission. Grating spectra reveal nu…