 Subjects -> ASTRONOMY (Total: 94 journals)
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- Detection of CH+, CH and H2 Molecules in the Young Planetary Nebula IC
4997- Authors: N. Kameswara Rao; David L. Lambert, Arumalla B. S. Reddy, D. A. García-Hernández, Arturo Manchado, J. J. Díaz-Luis
First page: 074201
Abstract: We have detected CH + and CH molecular absorption lines from the youngcompact planetary nebula IC
4997 from high resolution optical spectra. A high-resolution infra-red ( H and K bands) spectrum
provides detection of H 2 emission lines among many other lines. The H 2 lines provide an excitation
temperature of 2100 K which may result from UV fluorescence in the envelope or from shocks formed at
the interface between an expanding outflow of ionized gas and the neutral envelope ejected when the
star was on the AGB. It is suggested that the CH + may result from the endothermic reaction C + H 2
→ CH + + H. Intriguingly, CH + and also CH show a higher expansion velocity than H 2 emission
suggesting they may be part of the post-shocked gas.
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-06-08T23:00:00Z
DOI: 10.1088/1538-3873/ab9097
Issue No: Vol. 132, No. 1013 (2020)
- Investigation on the Binary Millisecond Pulsars at Radio and γ-Ray
Wavelengths: Links with the
Orbital Parameters- Authors: De-Hua Wang; Cheng-Min Zhang, Shuang-Qiang Wang
First page: 074202
Abstract: We analyze the properties of the binary millisecond pulsars (BMSPs), detected at radio and γ -ray
wavelengths, and further probe their correlations with the binary orbital parameters and companion
masses to trace the possible evolutionary histories. We find that the BMSPs with the lowest-mass
companions, (0.006–0.06) M ⊙ , have short orbital periods P orb
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-06-08T23:00:00Z
DOI: 10.1088/1538-3873/ab9077
Issue No: Vol. 132, No. 1013 (2020)
- A Gaia Early DR3 Mock Stellar Catalog: Galactic Prior and Selection
Function- Authors: Jan Rybizki; Markus Demleitner, Coryn Bailer-Jones, Piero Dal Tio, Tristan Cantat-Gaudin, Morgan Fouesneau, Yang Chen, René Andrae, Léo Girardi, Sanjib Sharma
First page: 074501
Abstract: We present a mock stellar catalog, matching in volume, depth and data model the content of the
planned Gaia early data release 3 (Gaia EDR3). We have generated our catalog (GeDR3mock) using
galaxia , a tool to sample stars from an underlying Milky Way (MW) model or from N -body data. We
used an updated Besançon Galactic model together with the latest PARSEC stellar evolutionary tracks,
now also including white dwarfs. We added the Magellanic clouds and realistic open clusters with
internal rotation. We empirically modeled uncertainties based on Gaia DR2 (GDR2) and scaled them
according to the longer baseline in Gaia EDR3. The apparent magnitudes were reddened according to a
new selection of 3D extinction maps. To help with the Gaia selection function we provide all-sky
magnitude limit maps in G and BP for a few relevant GDR2 subsets together with the routines to
produce these maps for user-defined subsets. We supplement the catalog with photometry and extinc...
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-05-17T23:00:00Z
DOI: 10.1088/1538-3873/ab8cb0
Issue No: Vol. 132, No. 1013 (2020)
- Pixel-based Spectral Characterization of Mid-infrared Si Array Detectors
for Astronomical
Observations in Space- Authors: Takuro Tsuchikawa; Hidehiro Kaneda, Daisuke Ishihara, Takuma Kokusho, Takehiko Wada
First page: 074502
Abstract: Mid-infrared (IR) array detectors have been used for astronomical observations in space. However,
the uniformities of their spectral response curves have not been investigated in detail, the
understanding of which is important for spectroscopic observations using large array formats. We
characterize the spectral responses of all the pixels in IR array detectors using a Fourier
transform infrared spectrometer and cryogenic optics for measurements at high signal-to-noise
ratios. We measured the spectral responses of the Si:As impurity band conduction (IBC) array, a
flight back-up detector for AKARI/InfraRed Camera. As a result, we find that the Si:As array has
intrinsic variations in the spectral response along the row and column directions of the array. We
also find that the cutoff wavelength of the Si:As IBC array depends on the intensity of the incident
light.
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-05-17T23:00:00Z
DOI: 10.1088/1538-3873/ab8aa8
Issue No: Vol. 132, No. 1013 (2020)
- Robust Automated Photometry Pipeline for Blurred Images
- Authors: Weirong Huang; Zhou Xie, Wenjie Zhong, Ying Mei, Hui Deng, Yingbo Liu, Feng Wang
First page: 075001
Abstract: The primary task of the 1.26 m telescope jointly operated by the National Astronomical Observatory
and Guangzhou University is photometric observations of the g, r , and i bands. A data processing
pipeline system was set up with mature software packages, such as IRAF, SExtractor, and SCAMP, to
process approximately 5 GB of observational data automatically every day. However, the success ratio
was significantly reduced when processing blurred images owing to telescope tracking error; this, in
turn, significantly constrained the output of the telescope. We propose a robust automated
photometric pipeline (RAPP) software that can correctly process blurred images. Two key techniques
are presented in detail: blurred star enhancement and robust image matching. A series of tests
proved that RAPP not only achieves a photometric success ratio and precision comparable to those of
IRAF but also significantly reduces the data processing load and improves the efficiency.
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-05-17T23:00:00Z
DOI: 10.1088/1538-3873/ab8e9b
Issue No: Vol. 132, No. 1013 (2020)
- Data Analysis for Precision 21cm Cosmology
- Authors: Adrian Liu; J. Richard Shaw
First page: 062001
Abstract: The redshifted 21 cm line is an emerging tool in cosmology, in principle permitting
three-dimensional surveys of our universe that reach unprecedentedly large volumes, previously
inaccessible length scales, and hitherto unexplored epochs of our cosmic timeline. Large radio
telescopes have been constructed for this purpose, and in recent years there has been considerable
progress in transforming 21 cm cosmology from a field of considerable theoretical promise to one of
observational reality. Increasingly, practitioners in the field are coming to the realization that
the success of observational 21 cm cosmology will hinge on software algorithms and analysis
pipelines just as much as it does on careful hardware design and telescope construction. This review
provides a pedagogical introduction to state-of-the-art ideas in 21 cm data analysis, covering a
wide variety of steps in a typical analysis pipeline, from calibration to foreground subtraction to
map making to power spectrum es...
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-04-21T23:00:00Z
DOI: 10.1088/1538-3873/ab5bfd
Issue No: Vol. 132, No. 1012 (2020)
- Focal Plane Wavefront Sensing with the FAST TGV Coronagraph
- Authors: Benjamin L. Gerard; Christian Marois
First page: 064401
Abstract: The continual push to directly image exoplanets at lower masses and closer separations orbiting
around bright stars remains limited by both quasi-static and residual adaptive optics aberration. In
previous papers we have proposed a modification of the self-coherent camera (SCC) design to address
both of these limitations, called the Fast Atmospheric SCC Technique (FAST). In this paper we
introduce an additional modification to the FAST focal plane mask design, including the existing
Tip/tilt and Gaussian components and adding a charge four Vortex (TGV) component. In addition to
boosting SCC fringe signal-to-noise ratio (S/N) as in our previous design, we show that the FAST TGV
mask is also optimized to reach high contrast at separations closer to the star. In this paper we
use numerical simulations to consider the performance improvement on correcting quasi-static
aberration using this new mask compared to the previously proposed Tip/tilt+Gaussian mask. Using
active deformable m...
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-04-20T23:00:00Z
DOI: 10.1088/1538-3873/ab84c9
Issue No: Vol. 132, No. 1012 (2020)
- HiFLEx—A Highly Flexible Package to Reduce Cross-dispersed Echelle
Spectra- Authors: Ronny Errmann; Neil Cook, Guillem Anglada-Escudé, Sirinrat Sithajan, David Mkrtichian, Eugene Semenko, William Martin, Tabassum S. Tanvir, Fabo Feng, James L. Collett, Hugh R. A. Jones
First page: 064504
Abstract: We describe a flexible data reduction package for high resolution cross-dispersed echelle data. This
open-source package is developed in Python and includes optional GUIs for most of the steps. It does
not require any pre-knowledge about the form or position of the echelle-orders. It has been tested
on cross-dispersed echelle spectrographs between 13k and 115k resolution (bifurcated fiber-fed
spectrogaph ESO-HARPS and single fiber-fed spectrograph TNT-MRES). HiFLEx can be used to determine
radial velocities and is designed to use the TERRA package but can also control the radial velocity
packages such as CERES and SERVAL to perform the radial velocity analysis. Tests on HARPS data
indicates radial velocities results within ±3 m s −1 of the literature pipelines without any fine
tuning of extraction parameters.
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-05-03T23:00:00Z
DOI: 10.1088/1538-3873/ab8783
Issue No: Vol. 132, No. 1012 (2020)
- OASI: A Brazilian Observatory Dedicated to the Study of Small Solar System
Bodies—Some Results on
NEO’s Physical Properties- Authors: Eduardo Rondón; Daniela Lazzaro, Teresinha Rodrigues, Jorge M. Carvano, Fernando Roig, Filipe Monteiro, Plicida Arcoverde, Hissa Medeiros, José Silva, Flavia Jasmim, Mario De Prá, Pedro Hasselmann, Anderson Ribeiro, Jorge Dávalos, Roberto Souza
First page: 065001
Abstract: The distribution of professional observatories around the world is quite biased toward the Northern
Hemisphere, and this tendency is even more pronounced when considering those dedicated only to the
study of small solar system bodies. In the Southern Hemisphere, the IMPACTON project deployed the
Observatório Astronômico do Sertão de Itaparica (OASI), dedicated to the observation of minor bodies
of the solar system with emphasis on Near-Earth Objects (NEOs). The observatory is located at the
county of Itacuruba, in the Pernambuco State of Brazil, and operate a 1 m Cassegrain telescope.
Here, we present a complete characterization of the OASI instruments and the sky conditions during
the first eight years of operations. The limiting magnitudes are determined in the different
available filters. The median seeing results to be 1.″22, with a higher number of photometric nights
from April to October. We also give an overview of the results obtained from the OASI observations
and discu...
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-05-03T23:00:00Z
DOI: 10.1088/1538-3873/ab87a7
Issue No: Vol. 132, No. 1012 (2020)
- Research on the Double-peaked Emission-line Galaxies from LAMOST Survey
- Authors: Mengxin Wang
First page: 067001
Abstract: Description unavailable
Citation: Publications of the Astronomical Society of the Pacific
PubDate: 2020-05-17T23:00:00Z
DOI: 10.1088/1538-3873/ab895e
Issue No: Vol. 132, No. 1012 (2020)
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