The Importance of Having an Extended Point-spread Function in Low Surface-brightness Science

2020 ◽  
Vol 4 (8) ◽  
pp. 130
Author(s):  
Raúl Infante-Sainz ◽  
Ignacio Trujillo ◽  
Javier Román
Keyword(s):  
Point Spread Function ◽  
Surface Brightness ◽  
Point Spread ◽  
Low Surface Brightness ◽  
Spread Function ◽  
Extended Point

scholarly journals Surface Brightness Profiles of 68 Globular Clusters Derived From Electronic Camera Recordings

1980 ◽  
Vol 85 ◽  
pp. 459-460
Author(s):  
Gerald E. Kron ◽  
Katherine C. Gordon ◽  
Anthony V. Hewitt
Keyword(s):  
Point Spread Function ◽  
Globular Clusters ◽  
Surface Brightness ◽  
Naval Observatory ◽  
Point Spread ◽  
Spread Function ◽  
Spacial Information ◽  
Cluster Profiles ◽  
Star Images ◽  
The U.S

Images of 68 globular clusters have been recorded in 125 exposures made with the electronic camera of the U.S. Naval Observatory on the 24-inch, 40-inch and 61-inch reflecting telescopes at the Flagstaff Station. The images were electronically malfocussed to allow the integration of light from the fainter cluster stars without saturation of the central portions of the brighter star images. Spacial information thus lost was partly regained by subsequent linear deconvolution of the cluster profiles by means of a star profile used as the point spread function.

Optical disk readout analysis using an extended point-spread function

1999 ◽  
Author(s):  
Yoshiyuki Matsumoto ◽  
Kimihiro Saito ◽  
Kiyoshi Toyota ◽  
Satoshi Hineno ◽  
Noriaki Nishi
Keyword(s):  
Point Spread Function ◽  
Optical Disk ◽  
Point Spread ◽  
Spread Function ◽  
Extended Point

Optical Disk Readout Analysis Using an Extended Point Spread Function

2000 ◽  
Vol 39 (Part 1, No. 2B) ◽  
pp. 693-697 ◽  
Author(s):  
Kimihiro Saito ◽  
Kamon Uemura ◽  
Yoshiaki Kato ◽  
Satoshi Hineno ◽  
Yoshiyuki Matsumoto ◽  
...  
Keyword(s):  
Point Spread Function ◽  
Optical Disk ◽  
Point Spread ◽  
Spread Function ◽  
Extended Point

scholarly journals The effects of seeing on Sèrsic profiles

2001 ◽  
Vol 321 (2) ◽  
pp. 269-276 ◽  
Author(s):  
I. Trujillo ◽  
J. A. L. Aguerri ◽  
J. Cepa ◽  
C. M. Gutiérrez
Keyword(s):  
Point Spread Function ◽  
Surface Brightness ◽  
Analytical Form ◽  
The Real ◽  
Point Spread ◽  
Central Depression ◽  
Spread Function ◽  
Gaussian Point

Abstract The effects of seeing on the parameters of the Sèrsic profile are studied in an analytical form using a Gaussian point spread function. The surface brightness of Sèrsic profiles is proportional (in magnitudes) to r1/n. The parameter n serves to classify the type of profile and is related to the central luminosity concentration. It is the parameter most affected by seeing; furthermore, the value of n that can be measured is always smaller than the real one. It is shown that the luminosity density of the Sèrsic profile with n less than 0.5 has a central depression, which is physically unlikely. Also, the intrinsic ellipticity of the sources has been taken into account and we show that the parameters are dependent when the effects of seeing are non-negligible. Finally, a prescription for correcting raw effective radii, central intensities and n parameters is given.

scholarly journals The reports of thick discs’ deaths are greatly exaggerated

2018 ◽  
Vol 610 ◽  
pp. A5 ◽  
Author(s):  
S. Comerón ◽  
H. Salo ◽  
J. H. Knapen
Keyword(s):  
Point Spread Function ◽  
Surface Brightness ◽  
Scattered Light ◽  
Stellar Structure ◽  
High Mass ◽  
Central Mass ◽  
Thin Disc ◽  
Point Spread ◽  
Spread Function ◽  
Low Mass

Recent studies have made the community aware of the importance of accounting for scattered light when examining low-surface-brightness galaxy features such as thick discs. In our past studies of the thick discs of edge-on galaxies in the Spitzer Survey of Stellar Structure in Galaxies – the S4G – we modelled the point spread function as a Gaussian. In this paper we re-examine our results using a revised point spread function model that accounts for extended wings out to more than 2 .́ 5. We study the 3.6 μm images of 141 edge-on galaxies from the S4G and its early-type galaxy extension. Thus, we more than double the samples examined in our past studies. We decompose the surface-brightness profiles of the galaxies perpendicular to their mid-planes assuming that discs are made of two stellar discs in hydrostatic equilibrium. We decompose the axial surface-brightness profiles of galaxies to model the central mass concentration – described by a Sérsic function – and the disc – described by a broken exponential disc seen edge-on. Our improved treatment fully confirms the ubiquitous occurrence of thick discs. The main difference between our current fits and those presented in our previous papers is that now the scattered light from the thin disc dominates the surface brightness at levels below μ ~ 26 mag arcsec-2. We stress that those extended thin disc tails are not physical, but pure scattered light. This change, however, does not drastically affect any of our previously presented results: 1) Thick discs are nearly ubiquitous. They are not an artefact caused by scattered light as has been suggested elsewhere. 2) Thick discs have masses comparable to those of thin discs in low-mass galaxies – with circular velocities vc< 120 km s-1 – whereas they are typically less massive than the thin discs in high-mass galaxies. 3) Thick discs and central mass concentrations seem to have formed at the same epoch from a common material reservoir. 4) Approximately 50% of the up-bending breaks in face-on galaxies are caused by the superposition of a thin and a thick disc where the scale-length of the latter is the largest.

Point spread function based feature optimization and fusion for underwater objet recognition

2013 ◽  
Vol 26 (11) ◽  
pp. 944-952 ◽  
Author(s):  
Huibin Wang ◽  
Rong Zhang ◽  
Zhe Chen ◽  
Lizhong Xu ◽  
Jie Shen
Keyword(s):  
Point Spread Function ◽  
Point Spread ◽  
Spread Function ◽  
Feature Optimization
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