scholarly journals A multi-wavelength pipeline for pulsar observations

2017 ◽  
Vol 13 (S337) ◽  
pp. 394-395
Author(s):  
Maura Pilia ◽  
Alessio Trois ◽  
Matteo Bachetti ◽  
Alberto Pellizzoni ◽  
Elise Egron ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Astronomical Observatory ◽  
Electromagnetic Spectrum ◽  
Multi Wavelength

AbstractThe Astronomical Observatory in Cagliari (OAC) is a growing facility with a group devoted to pulsar studies across the electromagnetic spectrum. Taking advantage of this expertise we have worked to provide a suite of multi-wavelength software and databases for the observations of pulsars and compact Galactic objects at the Sardinia Radio Telescope (SRT, Bolli et al. 2015, Prandoni et al. 2017).

scholarly journals IPS Observations at Miyun Station, BAO

2001 ◽  
Vol 203 ◽  
pp. 580-582
Author(s):  
X.Z. Zhang ◽  
J.H. Wu
Keyword(s):  
Radio Telescope ◽  
Data Reduction ◽  
Astronomical Observatory ◽  
Paper Briefly ◽  
Preliminary Results

IPS observations have recently begun at Miyun Station, Beijing Astronomical Observatory. This paper briefly describes the radio telescope at Miyun Station, discusses the observation and the data reduction procedures and presents the preliminary results of observations on IPS source 3C48.

scholarly journals IPS Observations at Miyun Station, BAO

2001 ◽  
Vol 182 ◽  
pp. 189-192 ◽  
Author(s):  
J. Wu ◽  
X. Zhang ◽  
Y. Zheng
Keyword(s):  
Radio Telescope ◽  
Data Reduction ◽  
Astronomical Observatory ◽  
Paper Briefly ◽  
Preliminary Results

AbstractIPS observations have recently begun at Miyun Station, Beijing Astronomical Observatory. This paper briefly describes the radio telescope at Miyun Station, discusses the observation and the data reduction procedures, and presents the preliminary results of observations on IPS source 3C48.

scholarly journals Two-wavelength thermal–optical determination of light-absorbing carbon in atmospheric aerosols

2019 ◽  
Vol 12 (6) ◽  
pp. 3173-3182 ◽  
Author(s):  
Dario Massabò ◽  
Alessandro Altomari ◽  
Virginia Vernocchi ◽  
Paolo Prati
Keyword(s):  
Laser Diode ◽  
Atmospheric Aerosols ◽  
Direct Determination ◽  
Optical Transmittance ◽  
Carbonaceous Aerosol ◽  
Electromagnetic Spectrum ◽  
Multi Wavelength ◽  
Physics Department ◽  
The University

Abstract. Thermal–optical analysis is widely adopted for the quantitative determination of total (TC), organic (OC), and elemental (EC) carbon in atmospheric aerosol sampled by suitable filters. Nevertheless, the methodology suffers from several uncertainties and artifacts such as the well-known issue of charring affecting the OC–EC separation. In the standard approach, the effect of the possible presence of brown carbon, BrC, in the sample is neglected. BrC is a fraction of OC, usually produced by biomass burning with a thermic behavior intermediate between OC and EC. BrC is optically active: it shows an increasing absorbance when the wavelength moves to the blue–UV region of the electromagnetic spectrum. Definitively, the thermal–optical characterization of carbonaceous aerosol should be reconsidered to address the possible BrC content in the sample under analysis. We introduce here a modified Sunset Lab Inc. EC–OC analyzer. Starting from a standard commercial instrument, the unit has been modified at the physics department of the University of Genoa (Italy), making possible the alternative use of the standard laser diode at λ=635 nm and of a new laser diode at λ=405 nm. In this way, the optical transmittance through the sample can be monitored at both wavelengths. Since at shorter wavelengths the BrC absorbance is higher, a better sensitivity to this species is gained. The modified instrument also gives the possibility to quantify the BrC concentration in the sample at both wavelengths. The new unit has been thoroughly tested, with both artificial and real-world aerosol samples: the first experiment, in conjunction with the multi-wavelength absorbance analyzer (MWAA; Massabò et al., 2013, 2015), resulted in the first direct determination of the BrC mass absorption coefficient (MAC) at λ=405 nm: MAC =23±1 m2 g−1.

scholarly journals Radio Interference and Ejecting Techniques at Beijing Astronomical Observatory

2001 ◽  
Vol 196 ◽  
pp. 288-291
Author(s):  
X. Zhang ◽  
T. Piao ◽  
B. Peng ◽  
X. Wang
Keyword(s):  
Radio Telescope ◽  
Astronomical Observatory ◽  
Interference Rejection ◽  
Radio Interference ◽  
New Developments

In this paper, we first describe the situation of radio interference at the Miyun station in Beijing Astronomical Observatory, and then new developments in both hardware and software techniques of interference rejection for the Miyun Synthesis Radio Telescope (MSRT) are described.

scholarly journals X-ray Studies of Planetary Nebulae

2016 ◽  
Vol 12 (S323) ◽  
pp. 104-108
Author(s):  
Rodolfo Montez
Keyword(s):  
Mass Transfer ◽  
Planetary Nebulae ◽  
Central Star ◽  
Electromagnetic Spectrum ◽  
Stellar Winds ◽  
X Ray ◽  
New Directions ◽  
Multi Wavelength ◽  
Formation And Evolution ◽  
Compact Sources

AbstractX-ray emission from planetary nebulae (PNe) provides unique insight on the formation and evolution of PNe. Past observations and the ongoing Chandra Planetary Nebulae Survey (ChanPlaNS) provide a consensus on the two types of X-ray emission detected from PNe: extended and compact point-like sources. Extended X-ray emission arises from a shocked “hot bubble” plasma that resides within the nebular shell. Cooler than expected hot bubble plasma temperatures spurred a number of potential solutions with one emerging as the likely dominate process. The origin of X-ray emission from compact sources at the location of the central star is less clear. These sources might arise from one or combinations of the following processes: self-shocking stellar winds, spun-up binary companions, and/or accretion, perhaps from mass transfer, PN fallback, or debris disks. In the discovery phase, X-ray studies of PNe have mainly focused on the origin of the various emission processes. New directions incorporate multi-wavelength observations to study the influence of X-ray emission on the rest of the electromagnetic spectrum.

scholarly journals Radio Emission from Clusters of Galaxies

1967 ◽  
Vol 20 (6) ◽  
pp. 715 ◽  
Author(s):  
HM Tovmassian ◽  
IG Moiseev
Keyword(s):  
Radio Emission ◽  
Radio Telescope ◽  
Radio Astronomy ◽  
Mathematical Expectation ◽  
Astronomical Observatory ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Astronomy Observatory ◽  
Group 5 ◽  
East West

From Abell's (1958) list of clusters of galaxies, 137 clusters of distance group 5 were observed at 1410 MHz with the 210 ft radio telescope of the Australian National Radio Astronomy Observatory at Parkes. The detected radio sources were further confirmed hy observations at 2650 MHz with the same telescope and at 408 MHz with the east-west arm of the Mills Cross at the Molonglo Radio Astronomical Observatory. A total of 25 radio sources was detected within 5' arc of the centres of corresponding clusters of galaxies, while the mathematical expectation of the number of random coincidences with clusters is about two or three

scholarly journals The extraordinary composition of the blue comet C/2016 R2 (PanSTARRS)

2018 ◽  
Vol 619 ◽  
pp. A127 ◽  
Author(s):  
N. Biver ◽  
D. Bockelée-Morvan ◽  
G. Paubert ◽  
R. Moreno ◽  
J. Crovisier ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Heliocentric Distance ◽  
Abundance Ratio ◽  
Visible Spectroscopy ◽  
Production Rates ◽  
Sulfur Species ◽  
Upper Limits ◽  
Multi Wavelength ◽  
Rare Group

We present a multi-wavelength study of comet C/2016 R2 (PanSTARRS). This comet was observed on 23 and 24 January 2018 with the IRAM 30 m telescope, and in January to March 2018 with the Nançay radio telescope. Visible spectroscopy was performed in December 2017 and February 2018 with small amateur telescopes. We report on measurements of CO, CH3OH, H2CO and HCN production rates, and on the determination of the N2/CO abundance ratio. Several other species, especially OH, were searched for but not detected. The inferred relative abundances, including upper limits for sulfur species, are compared to those measured in other comets at about the same heliocentric distance of ~2.8 AU. The coma composition of comet C/2016 R2 is very different from all other comets observed so far, being rich in N2 and CO and dust poor. This suggests that this comet might belong to a very rare group of comets formed beyond the N2 ice line. Alternatively, comet C/2016 R2 (PanSTARRS) could be the fragment of a large and differentiated transneptunian object, with properties characteristic of volatile-enriched layers.

scholarly journals Multi-Wavelength Observations of EV Lacertae

2004 ◽  
Vol 219 ◽  
pp. 249-253
Author(s):  
Rachel A. Osten ◽  
Suzanne L. Hawley ◽  
Joel Allred ◽  
Christopher M. Johns-Krull ◽  
Christine Roark ◽  
...  
Keyword(s):  
Optical Observations ◽  
Electromagnetic Spectrum ◽  
Temperature Plasma ◽  
Optical Photometry ◽  
X Ray ◽  
Neupert Effect ◽  
Conflicting Evidence ◽  
Multi Wavelength ◽  
Flare Process ◽  
Ev Lac

We report on a large, multi-wavelength campaign to observe variability across the electromagnetic spectrum in the M dwarf flare star EV Lacertae, in 2001 September. The campaign involved X-ray (Chandra ACIS-S+HETG), UV (HST/STIS), and optical (McDonald) spectra, as well as optical photometry and multi-frequency radio (VLA) observations. EV Lac demonstrated both frequent and extreme variability during the course of the two day intensive recordings. Dispersed X-ray spectra confirm the metal underabundance seen in other active stars. The increase in continuum fluxes at short X-ray wavelengths during flare intervals compared to quiescent intervals signals the creation of high temperature plasma, a signature of the flare process. Multi-wavelength comparisons reveal interesting trends: X-ray flare frequencies are within the range predicted by optical observations, yet there is no correspondence between X-ray flares and optical flares in our data. Two UV flares occur during the rise stages of X-ray flares; a major radio flare is accompanied by a large optical flare, which has no apparent counterpart in the X-ray. The results give conflicting evidence for the applicability of the Neupert effect interpretation in stellar coronae.

Newly Installed Radio and Optical Telescopes in China

1991 ◽  
Vol 9 (1) ◽  
pp. 60-61
Author(s):  
Jing-Sheng Wang
Keyword(s):  
Magnetic Field ◽  
Radio Telescope ◽  
Solar Magnetic Field ◽  
Astronomical Observatory ◽  
Optical Telescope ◽  
Millimetre Wave ◽  
Infrared Telescope ◽  
Wave Radio ◽  
New Radio ◽  
Optical Telescopes

AbstractNew radio and optical telescopes installed in recent years in China are summarised. These include the 2.16-m optical telescope, the solar magnetic field telescope, the Miyun synthesis radio telescope, the 1.26-m infrared telescope (Beijing Astronomical Observatory), the 25-m radio telescope as the first station of China’s VLBI network, the 1.56-m astrometric telescope (Shanghai Observatory), and the 13.7-m millimetre wave radio telescope.

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