Search Publications
Polar Dust, Nuclear Obscuration, and IR SED Diversity in Type-1 AGNs
Lyu, Jianwei; Rieke, George H.
Despite the hypothesized similar face-on viewing angles, the infrared emission of type-1 active galactic nuclei (AGNs) has diverse spectral energy distribution (SED) shapes that deviate substantially from the well-characterized quasar templates. Motivated by the commonly seen UV-optical obscuration and the discovery of parsec-scale mid-IR polar du…
Toward Understanding the B[e] Phenomenon. VII. AS 386, a Single-lined Binary with a Candidate Black Hole Component
Reichart, D. E.; Miroshnichenko, A. S.; Manset, N. +24 more
We report the results of spectroscopic and photometric observations of the emission-line object AS 386. For the first time we found that it exhibits the B[e] phenomenon and fits the definition of an FS CMa type object. The optical spectrum shows the presence of a B-type star with the following properties: T eff = 11,000 ± 500 K, log L/L…
A Multi-instrument and Multi-wavelength High Angular Resolution Study of MWC 614: Quantum Heated Particles Inside the Disk Cavity
Monnier, John D.; Kraus, Stefan; Hinkley, Sasha +13 more
High angular resolution observations of young stellar objects are required to study the inner astronomical units of protoplanetary disks in which the majority of planets form. As they evolve, gaps open up in the inner disk regions and the disks are fully dispersed within ∼10 Myr. MWC 614 is a pretransitional object with a ∼10 au radius gap. We pre…
Discovery of an Extremely Luminous Dust-obscured Galaxy Observed with SDSS, WISE, JCMT, and SMA
Ueda, Junko; Kawabe, Ryohei; Saito, Toshiki +5 more
We present the discovery of an extremely luminous dust-obscured galaxy (DOG) at z spec = 3.703, WISE J101326.25+611220.1. This DOG is selected as a candidate of extremely luminous infrared (IR) galaxies based on the photometry from the Sloan Digital Sky Survey and Wide-field Infrared Survey Explorer. In order to derive its accurate IR l…
Using Star Clusters as Tracers of Star Formation and Chemical Evolution: The Chemical Enrichment History of the Large Magellanic Cloud
Chilingarian, Igor V.; Asa'd, Randa
The star formation (SFH) and chemical enrichment (CEH) histories of Local Group galaxies are traditionally studied by analyzing their resolved stellar populations in a form of color-magnitude diagrams obtained with the Hubble Space Telescope. Star clusters can be studied in integrated light using ground-based telescopes to much larger distances. T…
The Near-infrared CO Absorption Band as a Probe to the Innermost Part of an AGN-obscuring Material
Nakagawa, Takao; Baba, Shunsuke; Isobe, Naoki +1 more
We performed a systematic analysis of the 4.67 µm CO ro-vibrational absorption band toward nearby active galactic nuclei (AGNs) and analyzed the absorption profiles of 10 nearby galaxies collected from the AKARI and Spitzer spectroscopic observations that show the CO absorption feature by fitting a plane-parallel local thermal equilibrium ga…
Comprehensive Analysis of HD 105, A Young Solar System Analog
Marshall, J. P.; del Burgo, C.; Ertel, S. +5 more
HD 105 is a nearby, pre-main-sequence G0 star hosting a moderately bright debris disk (L dust/L ⋆ ∼ 2.6 × 10-4). The star and its surroundings might therefore be considered an analog of the young solar system. We refine the stellar parameters based on an improved Gaia parallax distance and identify it as a pre-main…
Long-lived Protoplanetary Disks in Multiple Systems: The VLA View of HD 98800
Duchêne, Gaspard; Ribas, Álvaro; Espaillat, Catherine C. +1 more
The conditions and evolution of protoplanetary disks in multiple systems can be considerably different from those around single stars, which may have important consequences for planet formation. We present Very Large Array (VLA) 8.8 mm (34 GHz) and 5 cm (6 GHz) observations of the quadruple system HD 98800, which consists of two spectroscopic bina…
Variability of Disk Emission in Pre-main-sequence and Related Stars. IV. Investigating the Structural Changes in the Inner Disk Region of MWC 480
Bayyari, Ammar; Russell, Ray W.; Sitko, Michael L. +8 more
We present five epochs of near-IR observations of the protoplanetary disk around MWC 480 (HD 31648) obtained with the SpeX spectrograph on NASA’s Infrared Telescope Facility between 2007 and 2013, inclusive. Using the measured line fluxes in the Pa β and Br γ lines, we found the mass accretion rates to be (1.26-2.30) × 10-7 M ⊙
A Cavity of Large Grains in the Disk around the Group II Herbig Ae/Be Star HD 142666
Rubinstein, A. E.; Calvet, N.; Zhang, K. +3 more
Herbig Ae/Be (HAeBe) stars have been classified into Group I or Group II, and were initially thought to be flared and flat disks, respectively. Several Group I sources have been shown to have large gaps, suggesting ongoing planet formation, while no large gaps have been found in the disks of Group II sources. We analyzed the disk around the Group …