Search Publications
A Detailed Analysis of the Cloud Structure and Dynamics in Aquila Rift
Nakamura, Fumitaka; Dobashi, Kazuhito; Shimoikura, Tomomi +1 more
We present maps in several molecular emission lines of a 1 square degree region covering the W40 and Serpens South molecular clouds belonging to the Aquila Rift complex. The observations were made with the 45 m telescope at the Nobeyama Radio Observatory. We found that the 12CO and 13CO emission lines consist of several veloc…
Mapping local interstellar medium with diffuse interstellar bands
Paunzen, Ernst; Piecka, Martin
With the use of the data from archives, we studied the correlations between the equivalent widths of four diffuse interstellar bands (4430, 5780, 5797, 6284 $\mathring{\rm A}$ ) and properties of the target stars (colour excess values, distances, and Galactic coordinates). Many different plots of the diffuse interstellar bands and their maps were …
An Information Theory Approach on Deciding Spectroscopic Follow-ups
Astudillo, Javiera; Protopapas, Pavlos; Pichara, Karim +1 more
Classification and characterization of variable phenomena and transient phenomena are critical for astrophysics and cosmology. These objects are commonly studied using photometric time series or spectroscopic data. Given that many ongoing and future surveys are conducted in a time domain, and given that adding spectra provides further insights but…
Kinematic Properties of Young Intermediate- and Low-Mass Stars from the Gaia DR2 Catalogue
Bobylev, V. V.; Bajkova, A. T.
We have studied the kinematic properties of young pre-main-sequence stars. We have selected these stars based on data from the Gaia DR2 catalogue by invoking a number of photometric infrared surveys. Using 4564 stars with parallax errors less than 20%, we have found the following parameters of the angular velocity of Galactic rotation: km s-1…
The Herschel SPIRE Fourier Transform Spectrometer Spectral Feature Finder - IV. Neutral carbon detection in the SPIRE FTS spectra
Valtchanov, Ivan; Scott, Jeremy P.; Spencer, Locke D. +2 more
The SPIRE Fourier Transform Spectrometer (FTS) Spectral Feature Finder (FF), developed within the Herschel Spectral and Photometric Imaging Receiver (SPIRE) FTS instrument team, is an automated spectral feature fitting routine that attempts to find significant features in SPIRE FTS spectra. The 3P1-3P0 a…
Magnetic and Velocity Field Topology in Active Regions of Descending Phase of Solar Cycle 23
Maurya, R. A.; Ambastha, A.
We analyze the topology of photospheric magnetic fields and sub-photospheric flows of several active regions (ARs) that are observed during the peak to descending phase of Solar Cycle 23. Our analysis shows clear evidence of hemispheric preferences in all the topological parameters such as the magnetic, current and kinetic helicities, and the `cur…
The Hubble Space Telescope's Near-UV and Optical Transmission Spectrum of Earth as an Exoplanet
Roberge, Aki; France, Kevin; Youngblood, Allison +3 more
We observed the 2019 January total lunar eclipse with the Hubble Space Telescope's STIS spectrograph to obtain the first near-UV (1700-3200 Å) observation of Earth as a transiting exoplanet. The observatories and instruments that will be able to perform transmission spectroscopy of exo-Earths are beginning to be planned, and characterizing the tra…
Changes in the Period of the Population II Cepheid CC Lyr
Berdnikov, L. N.; Pastukhova, E. N.; Yacob, A. M.
The reduction of all the available photometry for the Cepheid CC Lyr has allowed its $O-C$ diagram spanning a time interval of 124 years to be constructed. The data obtained provide evidence for the existence of large random fluctuations in the period ($\varepsilon/P≈ 0.046$). A formal fitting of the $O-C$ residuals has made it possible to estimat…
Softening of the Metagalactic Ionizing Background from Internal He II Absorption in Quasars
Shull, J. Michael; Danforth, Charles W.
Quasars and other active galactic nuclei (AGN) are significant contributors to the metagalactic ionizing background at redshifts z < 3. Recent Hubble Space Telescope (HST)/Cosmic Origins Spectrograph (COS) composite spectra of AGN find a harder flux distribution in the Lyman continuum, ${F}_{\nu }\propto {\nu }^{-{\alpha }_{s}}$ (αs …
The evolutionary status of chemically peculiar eclipsing binary star DV Boo
Aliçavuş, F.; Kahraman Aliçavuş, Filiz
Eclipsing binary systems are unique stellar objects to examine and understand stellar evolution and formation. Thanks to these systems, the fundamental stellar parameters (mass, radius) can be obtained very precisely. The existence of metallic-line (Am) stars in binaries is noticeably common. However, the known number of Am stars in eclipsing bina…