Search Publications
Rest-frame Optical Spectra and Black Hole Masses of 3 < z < 6 Quasars
Goto, Tomotsugu; Nakagawa, Takao; Fan, Xiaohui +11 more
We present the rest-frame optical spectral properties of 155 luminous quasars at 3.3 < z < 6.4 taken with the AKARI space telescope, including the first detection of the Hα emission line as far out as z ∼ 6. We extend the scaling relation between the rest-frame optical continuum and the line luminosity of active galactic nuclei (AGNs) to the…
Circumstellar Dust around AGB Stars and Implications for Infrared Emission from Galaxies
Conroy, Charlie; Johnson, Benjamin D.; Villaume, Alexa
Stellar population synthesis (SPS) models are used to infer many galactic properties including star formation histories, metallicities, and stellar and dust masses. However, most SPS models neglect the effect of circumstellar dust shells around evolved stars and it is unclear to what extent they impact the analysis of spectral energy distributions…
Reanalysis of the Near-infrared Extragalactic Background Light Based on the IRTS Observations
Matsumoto, T.; Pyo, J.; Kim, M. G. +1 more
We reanalyze data of the near-infrared background taken by IRTS using up-to-date observational results of zodiacal light (ZL), integrated star light, and diffuse Galactic light. We confirm the existence of residual isotropic emission, which is slightly lower but almost the same as previously reported. At wavelengths longer than 2 µm, the res…
Identification of a Class of Low-mass Asymptotic Giant Branch Stars Struggling to Become Carbon Stars in the Magellanic Clouds
Boyer, Martha L.; Sonneborn, George; van Loon, Jacco Th. +4 more
We have identified a new class of Asymptotic Giant Branch (AGB) stars in the Small and Large Magellanic Clouds (SMC/LMC) using optical to infrared photometry, light curves, and optical spectroscopy. The strong dust production and long-period pulsations of these stars indicate that they are at the very end of their AGB evolution. Period-mass-radius…
Detections of Trans-Neptunian Ice in Protoplanetary Disks
Manoj, P.; Watson, D. M.; Sargent, B. +6 more
We present Herschel Space Observatory PACS spectra of T Tauri stars, in which we detect amorphous and crystalline water ice features. Using irradiated accretion disk models, we determine the disk structure and ice abundance in each of the systems. Combining a model-independent comparison of the ice feature strength and disk size with a detailed an…
Resolving the Bright HCN(1-0) Emission toward the Seyfert 2 Nucleus of M51: Shock Enhancement by Radio Jets and Weak Masing by Infrared Pumping?
Matsushita, Satoki; Lim, Jeremy; Krips, Melanie +3 more
We present high angular resolution observations of the HCN(1-0) emission (at ~1'' or ~34 pc), together with CO J = 1-0, 2-1, and 3-2 observations, toward the Seyfert 2 nucleus of M51 (NGC 5194). The overall HCN(1-0) distribution and kinematics are very similar to that of the CO lines, which have been indicated as the jet-entrained molecular gas in…
Origin of Interplanetary Dust through Optical Properties of Zodiacal Light
Ishiguro, Masateru; Yang, Hongu
This study investigates the origin of interplanetary dust particles (IDPs) through the optical properties, albedo and spectral gradient, of zodiacal light. The optical properties were compared with those of potential parent bodies in the solar system, which include D-type (as analogs of cometary nuclei), C-type, S-type, X-type, and B-type asteroid…
Measurements of the Mean Diffuse Galactic Light Spectrum in the 0.95-1.65 µm Band from CIBER
Lee, H. M.; Bock, J.; Cooray, A. +14 more
We report measurements of the diffuse galactic light (DGL) spectrum in the near-infrared, spanning the wavelength range 0.95-1.65 µm by the Cosmic Infrared Background ExpeRiment. Using the low-resolution spectrometer calibrated for absolute spectro-photometry, we acquired long-slit spectral images of the total diffuse sky brightness toward s…
Galaxy Evolution in the Mid-infrared Green Valley: A Case of the A2199 Supercluster
Diaferio, Antonaldo; Lee, Myung Gyoon; Hwang, Ho Seong +4 more
We study the mid-infrared (MIR) properties of the galaxies in the A2199 supercluster at z = 0.03 to understand the star formation activity of galaxy groups and clusters in the supercluster environment. Using the Wide-field Infrared Survey Explorer data, we find no dependence of mass-normalized integrated star formation rates of galaxy groups/clust…
AKARI Observation of the Sub-degree Scale Fluctuation of the Near-infrared Background
Lee, Hyung Mok; Lee, Myung Gyoon; Jeong, W. -S. +3 more
We report spatial fluctuation analysis of the sky brightness in the near-infrared from observations toward the north ecliptic pole (NEP) by the AKARI at 2.4 and 3.2 µm. As a follow-up study of our previous work on the Monitor field of AKARI, we used NEP deep survey data, which covered a circular area of about 0.4 square degrees, in order to …