J/ApJS/163/282 Molecular hydrogen column densities (Wakker+, 2006)
A FUSE survey of high-latitude galactic molecular hydrogen.
Wakker B.P.
<Astrophys. J. Suppl. Ser., 163, 282-305 (2006)>
=2006ApJS..163..282W 2006ApJS..163..282W
ADC_Keywords: Interstellar medium
Keywords: Galaxy: disk - Galaxy: halo - ISM: general - ISM: molecules -
ultraviolet: ISM
Abstract:
Measurements of molecular hydrogen (H2) column densities are
presented for the first six rotational levels (J=0-5) for 73
extragalactic targets observed with the Far Ultraviolet Spectroscopic
Explorer (FUSE). All of these have a final signal-to-noise ratio
larger than 10 and are located at Galactic latitude |b|>20°. The
individual observations were calibrated with the FUSE calibration
pipeline CalFUSE version 2.1 or higher and then carefully aligned in
velocity. The final velocity shifts for all the FUSE segments are
listed. H2 column densities or limits are determined for the six
lowest rotational (J) levels for each HI component in the line of
sight, using a curve-of-growth approach at low column densities
(<16.5) and Voigt-profile fitting at higher column densities.
Detections include 65 measurements of low-velocity H2 in the
Galactic disk and lower halo. Eight sight lines yield nondetections
for Galactic H2.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 105 180 Target exposure list
table2.dat 106 73 Velocities and signal-to-noise ratios
table3.dat 159 133 H2 measurements
table4.dat 100 24 H2 outside the Milky Way Disk
--------------------------------------------------------------------------------
See also:
B/fuse : The FUSE Observation Log (FUSE, 1999-2007)
J/ApJS/146/1 : O VI absorption in FUSE survey (Wakker+, 2003)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name Object name
16- 21 F6.2 deg GLON Galactic longitude
23- 28 F6.2 deg GLAT Galactic latitude
30- 43 A14 --- Type Target type
45- 52 A8 --- Set FUSE data set
53 A1 --- f_Set [c] Observed in the MDRS aperture, rather
than in the LWRS aperture
55- 57 F3.1 --- Cal Version of the calibration pipeline used
59- 63 F5.1 ks Exp Nominal exposure time
65- 68 F4.1 ks Exp1 ? Exposure time
69- 71 A3 --- f_Exp1 Flag on Exp1 (1)
73- 76 F4.1 ks Exp2 ? Exposure time
77 A1 --- f_Exp2 Flag on Exp2 (1)
79- 81 I3 10km/s/nm LiF1A ? Shift on LiF1A detector (987-1082Å)
82 A1 --- f_LiF1A [d] Flag on LiF1A (2)
84- 86 I3 10km/s/nm LiF1B ? Shift on LiF1A detector (1094-1187Å)
87 A1 --- f_LiF1B [d] Flag on LiF1B (2)
89- 91 I3 10km/s/nm LiF2A ? Shift on LiF2A detector (1085-1181Å)
92 A1 --- f_LiF2A [d] Flag on LiF2A (2)
94- 96 I3 10km/s/nm LiF2B ? Shift on LiF2B detector (983-1074Å)
97 A1 --- f_LiF2B [d] Flag on LiF2B (2)
99-101 I3 10km/s/nm SiC2A ? Shift on SiC2A detector (917-1006Å)
103-105 I3 10km/s/nm SiC2B ? Shift on SiC2B detector (1017-1105Å)
--------------------------------------------------------------------------------
Note (1): Flag on Exp1, Exp2, defined as follows:
a = Usable exposure time in LiF1A segment >10% less than nominal time
b = Usable exposure time in LiF2A segment >10% less than nominal time
Note (2): A "d" indicates observations for which some segments show a clear
slope in the centroid vs. wavelength plot; specifically
(in units of km/s/Å):
-----------------------------------------------------------------
ESO 141-G55 I9040104 (1999-10-16): 1alif=0.1206, 1blif=0.2395,
2alif=0.2336, 2blif=0.1094;
H1821+643 P1016405 (1999-10-13): 1alif=0.1108, 2blif=0.1643;
Mrk 335 P1010204 (2000-11-21): 1alif=0.1179, 2blif=0.1113;
Mrk 509 X0170101 (1999-11-02): 1alif=0.1539, 1blif=0.1590,
2alif=0.2923, 2blif=0.1565;
Mrk 876 P1073101 (1999-10-16): 1alif=0.1383, 2blif=0.1597;
MS 0700.7+6338 P2072701 (2000-01-10): 1alif=0.1721;
NGC 604 B0180201 (2001-09-03): 1alif=0.1876;
PG 0804+761 P1011901 (1999-10-05): 1alif=0.1691, 2blif=0.1149;
VII Zw 118 P1011604 (1999-10-06): 1alif=0.1149, 2blif=0.1377.
-----------------------------------------------------------------
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name Object name
16- 21 F6.2 deg GLON Galactic longitude
23- 28 F6.2 deg GLAT Galactic latitude
30- 34 F5.2 0.1fW/m2/nm Flux Flux density near 1031Å
(in units of 10-14erg/cm2/s/Å)
35 A1 --- f_Flux [a] a if flux near 1063Å
37- 41 F5.2 --- S/N(1031) Signal-to-noise ratio at 1031Å
43- 47 F5.2 --- S/N(1063) Signal-to-noise ratio at 1063Å
49- 53 F5.2 --- S/N(977) Signal-to-noise ratio at 977Å
55- 59 F5.2 --- S/N(1122) Signal-to-noise ratio at 1122Å
61- 64 I4 km/s V(HI)1 Velocities of the HI components found
in the 21cm spectra (1)
66- 69 I4 km/s V(HI)2 Velocities of the HI components found
in the 21cm spectra (1)
71- 73 I3 km/s V(HI)3 ? Velocities of the HI components found
in the 21cm spectra (1)
75- 77 I3 km/s V(HI)4 ? Velocities of the HI components found
in the 21cm spectra (1)
79- 82 I4 km/s V(M)1 ? The metal-line velocities that can be
derived from the alignment method
83 A1 --- f_V(M)1 [>:] Mean value (>) or uncertainty (:)
84 A1 --- n_V(M)1 [bcde] Note on V(metal)1 (2)
85- 88 I4 km/s V(M)2 ? The metal-line velocities that can be
derived from the alignment method
90- 92 I3 km/s V(M)3 ? The metal-line velocities that can be
derived from the alignment method
94- 96 I3 km/s V(M)4 ? The metal-line velocities that can be
derived from the alignment method
98-101 I4 km/s V(H2)1 ? H2 velocity
103-106 I4 km/s V(H2)2 ? H2 velocity
108-110 I3 km/s V(H2)3 ? H2 velocity
112-120 A9 --- Inst Instrument used (3)
--------------------------------------------------------------------------------
Note (1): which can be found in Wakker et al. (2003, Cat. J/ApJS/146/1).
Note (2): Notes as follows:
b = Average between 20 and 1km/s
c = Uncertain velocity: broad ISM lines without easily recognizable
components
d = Average between 11 and 45km/s
e = Average between 26 and 8km/s
Note (3): Instrument used, defined as follows:
E140M = there is STIS data from which V(metal) follows, and the FUSE and
STIS metal lines can be aligned, implying V(H2). In this case
v(HI) can be different from V(metal).
21 cm = the FUSE metal lines were aligned with the 21cm data.
21 cm -H2 = it was assumed that the H2 aligns with a bright, narrow
component in the 21cm HI spectrum.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name Object name (1)
16 A1 --- f_Name [d] Flag on Name (2)
18- 21 I4 km/s V(H2) The H2 velocity
23 A1 --- l_logN(J=0) Limit flag on logN(J=0)
24- 28 F5.2 [cm-2] logN(J=0) Log of H2 J=0 column density
30- 33 F4.2 [cm-2] e_logN(J=0) ? Lower uncertainty limit on logN(J=0)
35- 38 F4.2 [cm-2] E_logN(J=0) ? Upper uncertainty limit on logN(J=0)
40 A1 --- l_logN(J=1) Limit flag on logN(J=0)
41- 45 F5.2 [cm-2] logN(J=1) Log of H2 J=1 column density
47- 50 F4.2 [cm-2] e_logN(J=1) ? Lower uncertainty limit on logN(J=1)
52- 55 F4.2 [cm-2] E_logN(J=1) ? Upper uncertainty limit on logN(J=1)
57 A1 --- l_logN(J=2) Limit flag on logN(J=0)
58- 62 F5.2 [cm-2] logN(J=2) Log of H2 J=2 column density
64- 67 F4.2 [cm-2] e_logN(J=2) ? Lower uncertainty limit on logN(J=2)
69- 72 F4.2 [cm-2] E_logN(J=2) ? Upper uncertainty limit on logN(J=2)
74 A1 --- l_logN(J=3) Limit flag on logN(J=0)
75- 79 F5.2 [cm-2] logN(J=3) Log of H2 J=3 column density
81- 84 F4.2 [cm-2] e_logN(J=3) ? Lower uncertainty limit on logN(J=3)
86- 89 F4.2 [cm-2] E_logN(J=3) ? Upper uncertainty limit on logN(J=3)
91 A1 --- l_logN(J=4) Limit flag on logN(J=0)
92- 96 F5.2 [cm-2] logN(J=4) Log of H2 J=4 column density
98-101 F4.2 [cm-2] e_logN(J=4) ? Lower uncertainty limit on logN(J=4)
103-106 F4.2 [cm-2] E_logN(J=4) ? Upper uncertainty limit on logN(J=4)
108 A1 --- l_logN(H2) Limit flag on logN(H2)
109-113 F5.2 [cm-2] logN(H2) Log of H2 column density
115-118 F4.2 [cm-2] e_logN(H2) ? Lower uncertainty limit on logN(H2)
120-123 F4.2 [cm-2] E_logN(H2) ? Upper uncertainty limit on logN(H2)
125-128 F4.1 km/s W Full width at half maximum (3)
129 A1 --- f_W [)] Flag on W (4)
131-133 F3.1 km/s e_W ? Lower uncertainty limit on W
135-137 F3.1 km/s E_W ? Upper uncertainty limit on W
139-144 F6.2 km/s Wf ? Full width at half maximum from
curve-of-growth (5)
146-148 I3 K T01 ? H2 J(0,1) ratio temperature
149 A1 --- f_T01 [)] Flag on T01 (6)
151-153 I3 K T23 ? H2 J(2,3) ratio temperature
154 A1 --- f_T23 [)] Flag on T23 (6)
156-158 I3 K T34 ? H2 J(3,4) ratio temperature
159 A1 --- f_T34 [)] Flag on T34 (6)
--------------------------------------------------------------------------------
Note (1): Sightlines where lines of J=5 are detected:
ESO141-G55 = logN(J=5)=14.32-0.22+0.17;
HS0624+6907 = logN(J=5)=14.67-0.25+0.35;
Mrk116 = logN(J=5)=14.47-0.21+0.22;
Mrk876 = logN(J=5)=13.94-0.12+0.08;
Mrk1095 = logN(J=5)=14.53-0.20+0.18;
NGC3783 = logN(J=5)=14.24-0.08+0.10;
NGC4151 = logN(J=5)=13.45-0.25+0.16;
NGC5253 = logN(J=5)=14.23-0.14+0.13;
NGC7714 = logN(J=5)=14.17-0.32+0.25;
PG1211+143 = logN(J=5)=13.98-0.11+0.12;
PHL1811 = logN(J=5)=14.36-0.15+0.12;
PKS0405-12 = logN(J=5)=14.05-0.19+0.15.
Note (2): A "d" indicates that the listed errors for NGC 5236 and NGC 5253
do not include the systematic errors associated with the uncertain
continuum placements.
Note (3): Determined using the T12=T23 assumption.
Note (4): A ")" indicates that an FWHM of 9km/s was used to convert the
equivalent width limits into column density limits.
Note (5): Wf is the FWHM fitted by combining all H2 lines without damping
wings, rather than by assuming T12=T23. A value of -99.99
indicates that the line is on the linear part of the curve-of-growth.
Note (6): A ")" indicates temperature values that are not measured from
observed column density ratios, but that are expected values based on
the correlations shown in Fig. 6.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- f_Name Cloud category (1)
3- 16 A14 --- Name Object name
18- 27 A10 --- Cloud Cloud name
29- 32 I4 km/s V(H2) ? H2 velocity
34 A1 --- l_logN(H2)p [<] Upper limit flag on logNp
35- 39 F5.2 --- logN(H2)p ? Published logN(H2)
41- 43 A3 --- --- [±]
45- 48 F4.2 --- e_logN(H2)p ? Error in logN(H2)p
50- 53 F4.1 km/s FWHMp ? FWHM (km/s) of published value
54 A1 --- n_FWHMp [L] for Linear part of the curve-of-growth
57- 61 F5.2 --- logN(H2) This paper logN(H2)
63- 65 A3 --- --- [±]
67- 70 F4.2 --- e_logN(H2) Error in logN(H2)
72- 75 F4.1 km/s FWHM ? This paper FWHM (km/s)
76 A1 --- n_FWHM [L] for Linear part of the curve-of-growth
79-100 A22 --- Note Note
--------------------------------------------------------------------------------
Note (1): Flag on Name, defined as follows:
a = Intermediate-Velocity H2
(Compared to Richter et al. 2001ApJ...562L.181R 2001ApJ...562L.181R)
b = H2 in High-Velocity Clouds
(Compared to Sembach et al. 2001AJ....121..992S 2001AJ....121..992S)
c = Extragalactic H2
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 03-Mar-2008