2MASS Extended Source Catalog Key Parameters

TABLE 1. 2MASS Extended Source Catalog Key Parameters

Parameter

Description

ra

right ascension (J2000) in degrees; based on peak pixel

dec

declination (J2000) in degrees; based on peak pixel

density

Atlas image stellar number density:

log(stars per deg²) with K_s < 14 mag

<band>_ba

<band> minor/major axis ratio fit to the 3 isophote

<band>_phi

<band> angle to 3 major axis (E of N)

j_chif_ellf

%chi-fraction for ellipse fit to 3 J-band isophote

k_chif_ellf

%chi-fraction for ellipse fit to 3 K_s-band isophote

sup_ba

minor/major axis ratio fit to 3 super-Atlas Image isophote

sup_phi

super-Atlas Image angle to major axis (E of N)

sup_chif_ellf

%chi-fraction for ellipse fit to super-Atlas Image 3 isophote

r_k20fe

20 mag/arcsec² isophotal-K_s fiducial

elliptical aperture semi-major axis

<band>_m_k20fe

<band> 20mag/arcsec² isophotal fiducial

elliptical aperture magnitude

<band>_msig_k20fe

<band> 1 uncertainty in <band>_m_k20fe

<band>_flg_k20fe

<band> confusion flag for <band>_m_k20fe

<band>_m_7

<band> 7´´ radius circular aperture magnitude

<band>_msig_7

<band> 1 uncertainty in 7´´ circular ap. mag

<band>_flg_7

<band> confusion flag for 7´´ circular ap. mag

<band>_peak

<band> peak pixel surface brightness (mag/arcs²)

<band>_5surf

<band> mean surface brightness (r 5´´ ) (mag/arcs²)

<band>_sc_sh

<band> "shape" score; a.k.a. SH

<band>_sc_wsh

<band> "wsh" score; a.k.a. WSH

<band>_sc_r23

<band> r23 score; a.k.a. R23

<band>_bisym_rat

<band> bi-symmetric flux ratio

<band>_bisym_chi

<band> bi-symmetric cross-correlation ²

e_score

extended source probability

(1.0 = fuzziest; 2.0 = pointlike)

g_score

galaxy probability (1.0 = fuzziest; 2.0 = pointlike)

Table Notes: <band> refers to the J, H and K_s bands.

Return to Section IV.5.

TABLE 1. 2MASS Extended Source Catalog Key Parameters
Parameter	Description
ra	right ascension (J2000) in degrees; based on peak pixel
dec	declination (J2000) in degrees; based on peak pixel
density	Atlas image stellar number density: log(stars per deg²) with K_s < 14 mag
<band>_ba	<band> minor/major axis ratio fit to the 3 isophote
<band>_phi	<band> angle to 3 major axis (E of N)
j_chif_ellf	%chi-fraction for ellipse fit to 3 J-band isophote
k_chif_ellf	%chi-fraction for ellipse fit to 3 K_s-band isophote
sup_ba	minor/major axis ratio fit to 3 super-Atlas Image isophote
sup_phi	super-Atlas Image angle to major axis (E of N)
sup_chif_ellf	%chi-fraction for ellipse fit to super-Atlas Image 3 isophote
r_k20fe	20 mag/arcsec² isophotal-K_s fiducial elliptical aperture semi-major axis
<band>_m_k20fe	<band> 20mag/arcsec² isophotal fiducial elliptical aperture magnitude
<band>_msig_k20fe	<band> 1 uncertainty in <band>_m_k20fe
<band>_flg_k20fe	<band> confusion flag for <band>_m_k20fe
<band>_m_7	<band> 7´´ radius circular aperture magnitude
<band>_msig_7	<band> 1 uncertainty in 7´´ circular ap. mag
<band>_flg_7	<band> confusion flag for 7´´ circular ap. mag
<band>_peak	<band> peak pixel surface brightness (mag/arcs²)
<band>_5surf	<band> mean surface brightness (r 5´´ ) (mag/arcs²)
<band>_sc_sh	<band> "shape" score; a.k.a. SH
<band>_sc_wsh	<band> "wsh" score; a.k.a. WSH
<band>_sc_r23	<band> r23 score; a.k.a. R23
<band>_bisym_rat	<band> bi-symmetric flux ratio
<band>_bisym_chi	<band> bi-symmetric cross-correlation ²
e_score	extended source probability (1.0 = fuzziest; 2.0 = pointlike)
g_score	galaxy probability (1.0 = fuzziest; 2.0 = pointlike)