Planetary Nebulae Detected in the AKARI Far-IR All-Sky Survey Maps

2018 ◽  
Vol 14 (S343) ◽  
pp. 522-524
Author(s):  
Toshiya Ueta ◽  
Ryszard Szczerba ◽  
Andrew G. Fullard ◽  
Satoshi Takita
Keyword(s):  
Planetary Nebulae ◽  
Correction Method ◽  
Point Spread ◽  
Sky Survey ◽  
Spread Function ◽  
Infrared Astronomical Satellite ◽  
Empirical Point ◽  
The University ◽  
Astronomical Satellite ◽  
Bright Source

AbstractThe AKARI Far-IR All-Sky Survey (AFASS) maps produced by the AKARI Infrared Astronomical Satellite enabled us to probe the far-IR sky for objects having surface brightnesses greater than a few to a couple of dozen MJy sr−1. Recently, we have verified that, if AFASS-measured fluxes are properly corrected for using the aperture correction method based on the empirical point-spread-function templates derived directly from the AFASS maps, point-source photometry measured from the AFASS maps reproduces fluxes in the AKARI bright source catalogue (BSC). We have surveyed the far-IR sky in the AFASS for Galactic planetary nebulae (PNe) based on the University of Hong Kong/Australian Astronomical Observatory/Strasbourg Observatory Hα Planetary Nebula database (HASHPNDB), preliminarily yielding far-IR fluxes for roughly 1000 Galactic PNe including a few hundreds of PNe not listed in the AKARI/BSC.

scholarly journals Imaging of Magellanic Cloud Planetary Nebulae by the Hubble Space Telescope

1993 ◽  
Vol 155 ◽  
pp. 212-212
Author(s):  
M. A. Dopita ◽  
S. J. Meatheringham ◽  
P. R. Wood ◽  
H. C. Ford ◽  
R. C. Bohlin ◽  
...  
Keyword(s):  
Point Spread Function ◽  
Hubble Space Telescope ◽  
Planetary Nebulae ◽  
Magellanic Cloud ◽  
Space Telescope ◽  
Point Spread ◽  
Spread Function ◽  
Made In

We have obtained Hubble Space Telescope (HST) Planetary Camera (PC) images of a number of Magellanic Cloud planetary nebulae. The objects, except for SMP 83 were observed as part of the Cycle I GO program. The observations were made in the [O III] λ5007Å line. The object SMP 83, was observed as part of the GTO program, and in this case observations were also made in the Hα line using the F650N filter. In order to characterise the point spread function, a star was placed at the same point on the chip as the PN. This allowed us to determine the diameters of barely resolved PN in an accurate manner, by convolving the PSF with a function until it matched the appearance of the PN image. The results are given in Table 1.

Comparison of the distributions of galactic y-radiation and radio synchrotron radiation

1981 ◽  
Vol 301 (1462) ◽  
pp. 573-575 ◽  
Keyword(s):  
Radio Emission ◽  
Full Width Half Maximum ◽  
Detailed Comparison ◽  
Full Width ◽  
Half Maximum ◽  
Brightness Temperatures ◽  
Point Spread ◽  
Sky Survey ◽  
Spread Function ◽  
Continuum Radio

We have used the new all-sky survey of continuum radio emission at 408 MHz of Haslam et al. (1981 a, b ) to compare the distribution of radio emission in a band along the galactic equator for [ b ] < 20° with the COS-B y-ray distribution of Mayer-Hasselwander et al. (1980). The radio survey has resolution with full width half-maximum (f.w.h.m.) of 51 arc min and the data are brightness temperatures at 20' intervals in galactic coordinates. Such comparisons have been made before (see, for example, Jakel et al. 1975; Paul et al. 1976; Higdon 1979) with earlier y-ray data but this is the first in which the radio data have been in a form allowing a detailed comparison after convolution with the point spread function of the y-ray detector.

scholarly journals The AKARI Far-Infrared Surveyor (FIS): all–sky Diffuse Map

2010 ◽  
Vol 6 (S277) ◽  
pp. 1-4
Author(s):  
Shinya Komugi ◽  
Yasuo Doi ◽  
Makoto Hattori ◽  
Yoshimi Kitamura ◽  
Takafumi Otsubo ◽  
...  
Keyword(s):  
Image Data ◽  
Far Infrared ◽  
Spectral Energy ◽  
Long Wavelength ◽  
Calibration Uncertainty ◽  
Sky Survey ◽  
Spread Function ◽  
Nearby Galaxies ◽  
Astronomical Satellite ◽  
Better Than

AbstractThe infrared astronomical satellite AKARI performed an all sky survey at six infrared bands. We report here on the calibration of the all-sky image data, observed in the four long wavelength bands with the FIS instrument (AKARI Far-infrared All Sky Survey : AFASS). The preliminary image attains a calibration uncertainty and sensitivity of better than ~ 30% and ~ 10 MJy str−1, respectively, for all four bands. The point spread function (PSF) is obtained via a stacking technique. The data are shown to be useful for exploring the internal structure and dust spectral energy distributions (SEDs) of nearby galaxies.

scholarly journals Diffuse polarized emission in the LOFAR Two-meter Sky Survey

2019 ◽  
Vol 623 ◽  
pp. A71 ◽  
Author(s):  
C. L. Van Eck ◽  
M. Haverkorn ◽  
M. I. R. Alves ◽  
R. Beck ◽  
P. Best ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Depth Resolution ◽  
Polarization Data ◽  
Point Spread ◽  
Instrumental Polarization ◽  
Rotation Measure ◽  
Sky Survey ◽  
Spread Function ◽  
Polarized Emission ◽  
The Magnetic Field

Faraday tomography allows us to map diffuse polarized synchrotron emission from our Galaxy and use it to interpret the magnetic field in the interstellar medium (ISM). We have applied Faraday tomography to 60 observations from the LOFAR Two-meter Sky Survey (LOTSS) and produced a Faraday depth cube mosaic covering 568 square degrees at high Galactic latitudes, at 4.′3 angular resolution and 1 rad m−2 Faraday depth resolution, with a typical noise level of 50–100 μJy per point spread function (PSF) per rotation measure spread function (RMSF; 40–80 mK RMSF−1). While parts of the images are strongly affected by instrumental polarization, we observed diffuse polarized emission throughout most of the field, with typical brightness between 1 and 6 K RMSF−1, and Faraday depths between − 7 and +25 rad m−2. We observed many new polarization features, some up to 15° in length. These include two regions with very uniformly structured, linear gradients in the Faraday depth; we measured the steepness of these gradients as 2.6 and 13 rad m−2 deg−1. We also observed a relationship between one of the gradients and an H I filament in the local ISM. Other ISM tracers were also checked for correlations with our polarization data and none were found, but very little signal was seen in most tracers in this region. We conclude that the LOTSS data are very well suited for Faraday tomography, and that a full-scale survey with all the LOTSS data has the potential to reveal many new Galactic polarization features and map out diffuse Faraday depth structure across the entire northern hemisphere.

scholarly journals HIRAS: High-Resolution IRAS Images

1994 ◽  
Vol 158 ◽  
pp. 422-422
Author(s):  
Tj. Romke Bontekoe ◽  
Do Kester
Keyword(s):  
Diffraction Limit ◽  
Point Sources ◽  
Narrow Strip ◽  
Sky Survey ◽  
Infrared Astronomical Satellite ◽  
Significant Obstacle ◽  
Many Sources ◽  
Astronomical Satellite ◽  
Uniform Covering ◽  
Extended Emission

The InfraRed Astronomical Satellite (IRAS) all-sky survey was designed and optimized for the detection of point sources. This allowed the survey to be conducted in the form of narrow strip scans with redundant coverage of the sky, but with non-uniform covering densities. The data shows in addition to point sources many sources of extended emission, which are best analyzed from images. However, the non-uniform coverage now forms a significant obstacle in the image (re-)construction. Low resolution images, such as in the Infrared Sky Survey Atlas, yield spatial resolutions of 5–10 times the IRAS telescope diffraction limit; HIRAS improves this to 1–2 times!

scholarly journals QSO Color Selection in the SDSS

1998 ◽  
Vol 179 ◽  
pp. 291-292
Author(s):  
H. J. Newberg ◽  
B. Yanny
Keyword(s):  
Critical Path ◽  
Color Space ◽  
Sloan Digital Sky Survey ◽  
Radio Sources ◽  
Color Selection ◽  
The North ◽  
Point Spread ◽  
Sky Survey ◽  
Spread Function ◽  
North Galactic

The Sloan Digital Sky Survey (SDSS) will image 10,000 square degrees in the north galactic cap in five filters. We hope to identify and obtain spectra for about 100,000 quasars brighter than 20th magnitude in this area. The selection will be primarily on the basis of point spread function and colors, but we will also identify quasars from a catalog of FIRST radio sources. The selection areas in color space must be determined during the testing period prior to the official start of the survey. This task may determine the length of the test period. In anticipation of this becoming the critical path, we have written a body of software that will allow us to quickly analyze a set of multicolor data and make a first cut at the selection limits.

scholarly journals Infrared Observations of Galactic Planetary Nebulae

1989 ◽  
Vol 131 ◽  
pp. 9-16
Author(s):  
A. Preite-Martinez
Keyword(s):  
Planetary Nebulae ◽  
Major Event ◽  
Infrared Observations ◽  
Infrared Astronomical Satellite ◽  
Astronomical Satellite

Five months after the 1982 Symposium in London the InfraRed Astronomical Satellite (IRAS) was launched. Undoubtedly this has been the major event of the last five years in the infrared world, with a great impact in the field of Planetary Nebulae (PN) research (^).

scholarly journals A modified algorithm for Cleaning wide-field maps with extended structures

1991 ◽  
Vol 131 ◽  
pp. 242-242
Author(s):  
K. S. Dwarakanath ◽  
A. A. Deshpande ◽  
N. Udaya Shankar
Keyword(s):  
Point Spread Function ◽  
Dynamic Range ◽  
Computing Time ◽  
Point Sources ◽  
Aperture Synthesis ◽  
Wide Field ◽  
Point Spread ◽  
Sky Survey ◽  
Spread Function ◽  
Modified Algorithm

AbstractA simple but effective modification to the conventional CLEAN algorithm is suggested. This modification ensures both stability and speed when CLEAN is applied to maps containing a mixture of point sources and extended structures. The method has been successfully applied to the recently-completed sky survey at 34.5 MHz. This survey was made using the Gauribidanur T array (GEETEE) in 1-D aperture synthesis mode. Since in this case the ‘dirty beam’ (point spread function) cannot be directly computed, a method to obtain this is discussed in detail. The results of this deconvolution procedure have been encouraging in terms of reduced computing time and improved dynamic range in our maps. This algorithm should find wider application in deconvolving maps which have both extended structures and point sources.

scholarly journals X-raying the evolution of SN 1987A

2017 ◽  
Vol 12 (S331) ◽  
pp. 284-289
Author(s):  
Vinay L. Kashyap ◽  
David van Dyk ◽  
Katy McKeough ◽  
Frank Primini ◽  
Diab Jerius ◽  
...  
Keyword(s):  
Point Spread Function ◽  
Reconstruction Algorithm ◽  
Reconstruction Method ◽  
X Ray ◽  
Multi Scale ◽  
Sn 1987A ◽  
Point Spread ◽  
Spread Function ◽  
High Resolution Images ◽  
Empirical Point

AbstractSN 1987A has been observed with the Chandra X-ray Observatory over the entire course of the mission. We have re-analyzed the archival data by constructing an empirical point spread function and reconstructing high-resolution images using a Bayesian multi-scale image reconstruction algorithm. We are able to resolve structure in the equatorial ring of SN 1987A with unprecedented detail, at scales of $\approx \frac{1}{4}$ arcsec. We describe how the point spread function is constructed, and the reconstruction method, and explore the evolution of the inner ring at different epochs and passbands.

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