2010A&A...517L...9D

Query : 2010A&A...517L...9D

2010A&A...517L...9D - Astronomy and Astrophysics, volume 517, L9-9 (2010/7-1)

The H-test probability distribution revisited: improved sensitivity.

DE JAGER O.C. and BUESCHING I.

Abstract (from CDS):

To provide a significantly improved probability distribution for the H-test for periodicity in X-ray and γ-ray arrival times, which is already extensively used by the γ-ray pulsar community. Also, to obtain an analytical probability distribution for stacked test statistics in the case of a search for pulsed emission from an ensemble of pulsars where the significance per pulsar is relatively low, making individual detections insignificant on their own. This information is timely given the recent rapid discovery of new pulsars with the Fermi-LAT t γ-ray telescope. Approximately 1014 realisations of the H-statistic (H) for random (white) noise is calculated from a random number generator for which the repetition cycle is ≫1014. From these numbers the probability distribution P(>H) is calculated. The distribution of H is found to be exponential with parameter λ=0.4 so that the cumulative probability distribution P(>H)=((-λH)). If we stack independent values for H, the sum of K such values would follow the Erlang-K distribution with parameter λ for which the cumulative probability distribution is also a simple analytical expression. Searches for weak pulsars with unknown pulse profile shapes in the Fermi-LAT, Agile or other X-ray data bases should benefit from the H-test since it is known to be powerful against a broad range of pulse profiles, which introduces only a single statistical trial if only the H-test is used. The new probability distribution presented here favours the detection of weaker pulsars in terms of an improved sensitivity relative to the previously known distribution.

Abstract Copyright: ∼

Journal keyword(s): methods: statistical - pulsars: general

Simbad objects: 1

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Number of rows : 1
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024 		#notes
1 NAME Vela Pulsar Psr 08 35 20.65525 -45 10 35.1545     15.10     ~ 2314 1

Query : 2010A&A...517L...9D

Basic data :
NAME Vela Pulsar -- Pulsar
Origin of the objects types :

(Ref) Object type as listed in the reference "Ref"
(acronym) Object type linked to the acronym according to the original reference
() Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases

Other object types: 		gam (1AGL,2AGL,...), X (3A,2E,...), Psr (2010ApJS,PSR), Rad (Cul,ICRF,...), Ro* (2012A&A), V* (V*), SNR (SNR)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
ICRS coord. (ep=J2000) : 		08 35 20.65525 -45 10 35.1545 (Radio) [ 11.370 1.231 0 ] A 2004AJ....127.3587F
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
FK4 coord. (ep=B1950 eq=1950) : 		08 33 39.28984 -45 00 09.4529 [ 11.370 1.231 0 ]
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
Gal coord. (ep=J2000) : 		263.55197071 -02.78725587 [ 11.370 1.231 0 ]
Syntax of fluxes (or magnitudes) is : "filter-name (System) flux-value [error] quality MultVarFlags bibcode"
  • filter-name : U, B, V, R, I, G, J, H, K, u, g, r, i, z
  • (System) : may be AB (default is Vega)
  • flux-value : value of flux or magnitude
  • [error] : error value
  • quality : flag of quality of the flux value ( A=best quality -> E=worst quality, {� } =unknown quality)
  • MultVarFlags : Mult is zero or one char (J) for joined photometry ; Var can be zero or two chars (V[0-4])
  • bibcode : bibcode of the flux reference
Fluxes (1) :
V 15.10 [0.3] D 2012A&A...548A..79A
SIMBAD within arcmin
', {sourceSize:12, color:'#30a090'})); aladin.on('objectClicked', function(object) { var objName=object.data.MAIN_ID; aladin.showPopup(object.ra,object.dec,'',''+ objName+''); });" title="Show Simbad objects"> Overlay Simbad points in this preview
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within arcsec The VizieR photometry tool allows for easy visualization of photometry points extracted around the Simbad position from photometry-enabled catalogues in VizieR.
The search radius has to be specified by the user. It is currently limited to a maximum of 30 arcsec. It depends mostly on the precision or quality of the coordinates (SIMBAD and VizieR catalogs), the resolution of the images from which the sources were extracted, source extent, and source crowding.
Suggestions are: crowded field: 0.5 to 1.5 arcsec, 3 arcsec otherwise; uncertain coordinates (SIMBAD quality E or coordinates without reference): 5 to 30 arsec (risky!). sed-help-icon
Some important notes on this object about identifications and objects associations.
notes:

The link on the acronym of the identifiers give access to the information for this acronym in the dictionary of nomenclature.
Identifiers (49) :
An access of full data is available using the icon Vizier near the identifier of the catalogue

PSR J0834-4511 0FGL J0835.4-4510 IERS B0833-450 SNR G263.6-02.8
3A 0834-450 1FGL J0835.3-4510 INTEGRAL1 5 SWIFT J0835.2-4513
1AGL J0835-4509 2FGL J0835.3-4510 INTREF 358 SWIFT J0835.2-4511
2AGL J0835-4514 3FGL J0835.3-4510 1M 0833-450 2U 0832-45
1CG 263-02 4FGL J0835.3-4510 NAME Vel A 3U 0833-45
2CG 263-02 1FHL J0835.3-4510 NAME Vela PSR 4U 0833-45
Cul 0833-449 2FHL J0835.3-4511 NAME Vel Pulsar V* HU Vel
2E 2014 3FHL J0835.3-4510 NAME Vela Pulsar [BM83] X0833-450
2E 0833.6-4500 1FLE J0835-4507 PBC J0835.3-4511 [KRL2007b] 67
2EG J0835-4513 GAL 263.5-02.7 PSR B0833-45 EQ 0833-450
3EG J0834-4511 GeV J0835-4512 PSR J0835-4510
EGR J0834-4512 H 0833-450 RORF 0833-450
1ES 0833-45.0 ICRF J083520.6-451035 1RXS J083520.6-451035

References (2314 between 1850 and 2024) (Total 2314)
Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system).
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Collections of Measurements


V* : 1    distance : 2   

   

Observing logs


XMM : 3   

   

External archives :

Archive data at HEASARC - High-Energy Astrophysics Science Archive Research Center

Data at NED - NASA/IPAC Extragalactic Database : NAME Vela Pulsar

Link by name to the catalogue in VizieR :

2E 2014 3EG J0834-4511 IERS B0833-450 1RXS J083520.6-451035 V* HU Vel

Search by coordinates in Vizier (radius: 5 arcsec)

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