J/ApJS/176/59 FUSE survey of OVI in the disk of the Milky Way (Bowen+, 2008)
The Far Ultraviolet Spectroscopic Explorer survey of O VI absorption in
the disk of the Milky way.
Bowen D.V., Jenkins E.B., Tripp T.M., Sembach K.R., Savage B.D., Moos H.W.,
Oegerle W.R., Friedman S.D., Gry C., Kruk J.W., Murphy E., Sankrit R.,
Shull J.M., Sonneborn G., York D.G.
<Astrophys. J. Suppl. Ser., 176, 59-163 (2008)>
=2008ApJS..176...59B 2008ApJS..176...59B
ADC_Keywords: Interstellar medium ; Ultraviolet ; Milky Way
Keywords: Galaxy: disk - ISM: clouds - ISM: kinematics and dynamics
ISM: structure - ultraviolet: ISM
Abstract:
To probe the distribution and physical characteristics of interstellar
gas at temperatures T∼3x105K in the disk of the Milky Way, we have
used the Far Ultraviolet Spectroscopic Explorer (FUSE) to observe
absorption lines of OVIλ1032 toward 148 early-type stars
situated at distances >1kpc. After subtracting off a mild excess of
OVI arising from the Local Bubble, combining our new results with
earlier surveys of OVI, and eliminating stars that show conspicuous
localized X-ray emission, we find an average OVI midplane density
n0=1.3x10-8cm-3. The density decreases away from the plane of
the Galaxy in a way that is consistent with an exponential scale
height of 3.2kpc at negative latitudes or 4.6kpc at positive
latitudes.
Description:
Of the 148 stars in our sample, 111 were observed as part of PI Team
programs P102 and P122 (The properties of hot gas in the Milky Way and
Magellanic Clouds (Galactic Disk)), from 1999 November to 2003 August.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 116 148 *Stellar parameters for FUSE target stars
table4.dat 90 154 Voigt profile fits to detected OVI lines toward
target stars
refs.dat 43 24 References for table 1
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Note on table1.dat: Quantities which are taken from the Hipparcos/Tycho catalogs
were downloaded from Cat. I/239 from the VizieR Service.
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See also:
B/fuse : The FUSE Observation Log (FUSE, 1999-2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Running identification number (1)
5- 14 A10 --- Name Star name
16- 21 A6 --- P-ID Program identification (root of FUSE dataset)
23- 28 F6.2 deg GLON Galactic longitude
30- 35 F6.2 deg GLAT Galactic latitude
37- 41 F5.2 mag Bmag The Johnson B band magnitude (2)
43- 47 F5.2 mag Vmag The Johnson V band magnitude (2)
49 A1 --- f_Vmag [deg] Vmag corrected or variable (3)
51- 55 F5.2 mag Kmag ? The Johnson K band magnitude (4)
57- 67 A11 --- SpType MK spectral and luminosity type
69- 72 F4.2 mag E(B-V) ? The (B-V) color excess (5)
74- 77 F4.2 mag e_E(B-V) ? Uncertainty in E(B-V)
79- 83 F5.2 mag E(K-V) ? The (K-V) color excess
85- 88 F4.2 mag e_E(K-V) ? Uncertainty in E(K-V)
90- 93 F4.1 kpc Dist Heliocentric distance
95- 96 A2 --- n_Dist Origin of distance (6)
98-100 F3.1 kpc e_Dist Lower distance value (7)
102-105 F4.1 kpc E_Dist Upper distance value (7)
107-111 F5.1 km/s Vel Velocity correction (8)
113 I1 --- X [0/3] ROSAT classification (9)
115-116 I2 --- r_SpType Reference for SpType in refs.dat file
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Note (1): Corresponding to panel numbers shown in Fig. 24.
Note (2): Converted from Tycho BT and VT values.
Note (3): Flags as follows:
d = B and V magnitudes corrected; star is identified as a multiple system
in the Hipparcos Double and Multiples: Component solutions catalog.
Magnitude of the brightest given component used. Magnitude is actually
Hp, which we take to be close to Johnson-V (See Appendix B.1.1.).
e = B and V magnitudes corrected; star is not SB, but is listed as
variable in the Hipparcos Variability Annex. Faintest magnitude listed
is used. Magnitude is actually Hp, which we take to be close to
Johnson-V (See Appendix B.1.1).
g = Star is cataloged as variable in the GCVS by Samus et al. (2004,
Cat. II/250, superseded by Cat. B/gcvs). Magnitude is not corrected,
however (See Appendix B.1.3).
Note (4): Converted from 2MASS K-band magnitude. Value is not given if E(K-V)
was not derived for the sight line (see Appendix B.2).
Note (5): Not given if distance to star taken from literature.
Note (6): Flags as follows:
a = Star is identified as a spectroscopic binary (SB) either in the SB9
catalog Pourbaix et al. (2004, Cat. V/122) or by Garcia & Mermilliod
(2001A&A...368..122G 2001A&A...368..122G). Except for HD 114032 (where a Hipparcos distance
is used) the distance is corrected by a factor determined by the
prescription set out in Appendix B.1.2.
b = Distances to star taken from the literature for:
HD187282 = Arnal et al. (1999AJ....118.1798A 1999AJ....118.1798A);
HD190918 = van der Hucht (2001, Cat. III/215);
HD191765 = van der Hucht (2001, Cat. III/215);
HD005005A = Guetter & Turner (1997AJ....113.2116G 1997AJ....113.2116G);
LS277 = Reed (1993, Cat J/PASP/105/1465);
HD093129A = Tapia et al. (2003MNRAS.339...44T 2003MNRAS.339...44T);
HD110432 = Rachford et al. (2001ApJ...555..839R 2001ApJ...555..839R);
HD151932 = van der Hucht (2001, Cat. III/215).
c = Hipparcos parallax distance used.
Note (7): Based on the uncertainties discussed in Appendix B.3.
Note (8): Correction required to move heliocentric velocities observed along
a sight line to LSR velocities (VLSR=Vel+V☉).
Note (9): Code as follows:
0 = Target is in an X-ray-dark portion of the sky, well free of any emission
1 = Target is in or near a general diffuse enhancement of X-ray
emission or is on the edge of a bright spot
2 = Target is clearly situated in projection in a bright X-ray spot
that appears to have been created by the star and/or its
association neighbors
3 = Stars are situated inside the boundary of a SNR and are not
clearly in the foreground
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Running identification number (1)
5- 14 A10 --- Name Star name
16- 19 I4 km/s HRV Heliocentric velocity (2)
21- 24 F4.1 km/s blow Lower limit of b interval
26- 29 F4.1 km/s b Best Doppler parameter fit (b-parameter)
31- 34 F4.1 km/s bupp Upper limit of b interval
36- 38 F3.1 km/s sig-b Error in Doppler fit from noise (3)
40- 44 F5.1 km/s E_sig-b Upper final error in Doppler fit (4)
46- 50 F5.1 km/s e_sig-b Lower final error in Doppler fit (4)
52- 55 F4.2 10+14/cm2 Nlow Lower limit of N interval
57- 60 F4.2 10+14/cm2 N Best OVI column density fit
62- 65 F4.2 10+14/cm2 Nupp Upper limit of N interval
67- 70 F4.2 10+14/cm2 sig-N Error in OVI column density fit (3)
72- 76 F5.2 10+14/cm2 NT ? Total OVI column density (5)
78- 81 F4.2 10+14/cm2 E_NT ? Upper limit uncertainty in NT
83- 86 F4.2 10+14/cm2 e_NT ? Lower limit uncertainty in NT
88 A1 --- ZPF Zero-point flag (6)
90 I1 --- Cont ? [0/2] Continuum selection flag (7)
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Note (1): Corresponding to panel numbers shown in Fig. 24.
Note (2): Of Voigt-profile fit to the OVI absorption line.
Note (3): From Monte-Carlo simulations (Bowen et al., 1995ApJ...448..634B 1995ApJ...448..634B).
Note (4): Combining (b-blower) or (bupper-b) in quadrature with sig-b
(See section 2.8.1 for further details).
Note (5): Summed over all components. (If only one component was fitted, this
number is just a repeat of the value in column "N"). The final error
in the OVI column density follows in columns "E_NT" and "e_NT".
Note (6): Indication of correction applied to wavelength zero-point:
S = FUSE data shifted to match H2 lines flanking OVI (1032Å) line
with ClI (1347Å) line in STIS echelle data. For these data, the
uncertainty in the velocity of the measured absorption lines is
∼1.5-3.0km/s;
X = FPALXPOS>200, MDRS aperture used, or not LiF1a channel data (and no
STIS data available). Hence no correction made, and the error in the
velocity of the absorption lines is unknown;
F = LiF1a data taken through LWRS aperture, and FPALXPOS<200, so fixed
offset of +10km/s applied. The uncertainties in v are ∼5km/s.
See Appendix A for full details;
Note (7): Indicates potential ambiguity in the decisions made in selecting how
a continuum should be applied to the stellar flux, as follows:
0 = no ambiguity;
1 = continuum could have been chosen to follow a significantly different
path than the one adopted either side of the OVI line;
2 = continuum could have been chosen to follow a significantly different
path than the one adopted to the red side of the OVI. See Section 2.6
for a detailed schema of the selection of continua.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Num Reference number
4- 22 A19 --- BibCode Bibcode
24- 43 A20 --- Aut Author's name
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 17-Sep-2009