J/A+A/641/A35 Dark dust and single-cloud sightlines in ISM (Siebenmorgen+, 2020)
Dark dust and single-cloud sightlines in the ISM.
Siebenmorgen R., Krelowski J., Smoker J., Galazutdinov G., Bagnulo S.
<Astron. Astrophys., 641, A35 (2020)>
=2020A&A...641A..35S 2020A&A...641A..35S (SIMBAD/NED BibCode)
ADC_Keywords: Diffuse clouds ; Extinction ; Interstellar medium ; Spectroscopy ;
Line Profiles ; Reddening ; Stars, OB ; Stars, early-type
Keywords: ISM: clouds - dust, extinction - ISM: lines and bands -
stars: early-type
Abstract:
The precise characteristics of clouds and the nature of dust
in the diffuse interstellar medium can only be extracted by inspecting
the rare cases of single-cloud sightlines. In our nomenclature such
objects are identified by interstellar lines, such as KI, that show at
a resolving power of λΔλ∼75000 one dominating
Doppler component that accounts for more than half of the observed
column density. We searched for such sightlines using high-resolution
spectroscopy towards reddened OB stars for which far-UV extinction
curves are known. We compiled a sample of 186 spectra, 100 of which
were obtained specifically for this project with UVES. In our sample
we identified 65 single-cloud sightlines, about half of which were
previously unknown. We used the CH/CH+ line ratio of our targets to
establish whether the sightlines are dominated by warm or cold clouds.
We found that CN is detected in all cold (CH/CH+>1) clouds, but {is
frequently absent} in warm clouds. We inspected the WISE (3-22um)
observed emission morphology around our sightlines and excluded a
circumstellar nature for the observed dust extinction. We found that
most sightlines are dominated by cold clouds that are located far away
from the heating source. For 132 stars, we derived the spectral type
and the associated spectral type-luminosity distance. We also applied
the interstellar CaII distance scale, and compared these two distance
estimates with GAIA parallaxes. These distance estimates scatter by
∼40%. By comparing spectral type-luminosity distances with those of
GAIA, we detected a hidden dust component that amounts to a few mag of
extinction for eight sightlines. This dark dust is populated by ≳ 1um
large grains and predominately appears in the field of the cold
interstellar medium.
Description:
We present the normalised and where necessary telluric corrected
spectra of our sample in the Heliocentric rest frame for several
atomic and molecular lines as well as three tables showing the sample
and KI column densities for these and other sightlines.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This files
tablea1.dat 104 137 Study sample
tablea2.dat 71 174 UVES and FEROS archive spectra fitting
covering the KI line
tablea3.dat 113 231 Results summary
listsp.dat 70 658 List of normalised spectra of our UVES sample from
ESO programme 0102.C-0040(B) in the Heliocentric
rest frame for several atomic and molecular lines
sp/* . 658 Individal normalised spectra
listar.dat 146 102 Additional spectra in the KI line for UVES data
taken from the ESO archive, telluric corrected
ar/* . 102 Individual spectra in the KI line
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/136] Star identifier in the paper
5- 15 A11 --- Star Star name
18- 27 A10 --- AltName Star common name
29- 33 F5.2 mag Vmag V band magnitude
34- 38 F5.2 mag E(B-V) E(B-V) reddening
39- 43 F5.2 mag e_E(B-V) Error in E(B-V) reddening
44- 48 F5.2 mag AV Extinction in V
49- 53 F5.2 mag e_AV Error in extinction in V
54- 58 F5.2 km/s Rv Total to selective extinction
59- 63 F5.2 km/s e_Rv Error in total to selective extinction
64- 72 A9 --- SpTypeL Spectral type from the literature
73- 75 A3 --- r_SpTypeL Reference for spectral type from the
literature (1)
76- 95 A20 --- SpType Spectral type from this paper
96-102 A7 --- Inst Instrument used
103-104 A2 --- r_Inst Reference for instrument used (2)
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Note (1): References for spectral types as follows:
F = Fitzpatrick E. L., Massa D., 2007, Cat. J/ApJ/663/320
G = Gordon K. D., Cartledge S., Clayton G. C., 2009ApJ...705.1320G 2009ApJ...705.1320G
HS = Houk N., Swift C., 1999, Michigan Spectral Survey, 5.0, Cat. III/214
V = Valencic L.A., Clayton G.C., Gordon K.D., 2004ApJ...616..912V 2004ApJ...616..912V
Note (2): Reference for instrument used as follows:
a = This work
b = Cox N., Cami J., FarhangA., et al., 2017, Cat. J/A+A/606/A76
c = UVES prog ID 096.D-0008(A), (unpublished ESO archive)
d = UVES prog ID 099.C-0637(A), (unpublished ESO archive)
e = Bagnulo S., Cox N.L.J., Cikota A., et al., 2017, Cat. J/A+A/608/A146
f = Sembach K.R., Danks A.C., SAvage .D., 1993A&AS..100..107S 1993A&AS..100..107S
g = Welty D.E. Crowther P.A., 2010, Cat. J/MNRAS/404/1321
h = Tolstoy E., Venn K.A., Shetrone, M., et al., 2003AJ....125..707T 2003AJ....125..707T
i = Krelowski J., Beletsky Y., Galazutdinov G.A., et al., 2010ApJ...714L..64K 2010ApJ...714L..64K
j = SAO 1.0-m
k = SOPHIE archive
l = ELODIE archive
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/186] Star identifier in the paper
5- 14 A10 --- Star Star name
16- 17 A2 --- Type [S M Sa] Type (1)
18- 31 A14 --- ProgID Programme ID
32- 38 F7.2 km/s HV Heliocentric velocity, fit parameters of the
KI line profile
39- 43 F5.2 km/s e_HV Error in heliocentric velocity
44- 49 F6.2 km/s b b-value, fit parameters of the KI line profile
50- 54 F5.2 km/s e_b Error in b-value
55- 60 F6.2 [cm-2] logN Log10 of the column density, fit parameters
of the KI line profile
61- 65 F5.2 [cm-2] e_logN Error in the column density
66- 69 F4.1 km/s FWHM Instrumental Full Width Half Maximum
71 A1 --- n_Star [*] Mote on Star (2)
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Note (1): Type as follows:
S = Single cloud
M = dominated or multiple
Sa = single but with lower resolution
Note (2): HD 175156 is classified as single although the spectrum has
resolution of 5km/s (FWHM).
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/136] Star identifier in the paper
5- 14 A10 --- Star Star name
16- 17 A2 --- Res [HR LR] Resolution,
HR=high resolution, LR=low resolution
19 A1 --- Class [SM] Classification (1)
20- 24 I5 0.1pm EWCaK ?=-999 Equivalent width of the CaII K line
25- 29 I5 0.1pm e_EWCaK ?=-999 Error in the equivalent width of
the CaII K line
30- 34 I5 0.1pm EWCaH ?=-999 Equivalent width of the CaII H line
35- 39 I5 0.1pm e_EWCaH ?=-999 Error in the equivalent width of
the CaII H line
40- 44 I5 pc DistCaII ?=-999 Distance from CaII
45- 49 I5 pc E_DistCaII ?=-999 Positive error in distance from CaII
50- 54 I5 pc e_DistCaII ?=-999 Negative error in distance from CaII
55- 59 I5 pc DistGAIA ?=-999 Distance from GAIA
60- 64 I5 pc E_DistGAIA ?=-999 Positive error in distance from GAIA
65- 69 I5 pc e_DistGAIA ?=-999 Negative error in distance from GAIA
70- 74 I5 --- Sp/L ?=-999 Spectral type to luminosity ratio
76 A1 --- ClassCaII [SM-] Classification for CaK only (1)
78 A1 --- ClassNaI [SM-] Classification for NaI only (1)
80 A1 --- ClassKI [SM-] Classification for KI only (1)
81- 87 F7.2 km/s VHel Heliocentric velocity
88- 92 I5 [10+9cm-2] logNKI Log of KI column density (109/cm2)
93- 95 I3 [10+9cm-2] e_logNKI Error in log of KI column density
(109/cm2)
96-101 F6.1 0.1nm EWKI ?=-1 Equivalent width in milli Angstroms
for KI (7698 Angstroms)
102-105 F4.1 0.1nm e_EWKI ?=-1 Error in equivalent width in
milli Angstroms for KI (7698 Angstroms)
106-111 A6 --- Environ Classification of cloud environment as cold
(c) or warm (w) with or without
CNI detection
112-113 A2 --- ClassWise [abcde_] Infrared morphology of WISE (W4)
image
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Note (1): Classification as follows:
S = Single cloud dominated sightline
M = Multiple component sightline
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Byte-by-byte Description of file: listsp.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star name
11- 17 F7.4 --- Rv Ratio of total-to-selective extinction
19- 26 A8 --- Line Line
28- 35 F8.3 0.1nm lambda0 Rest wavelength
37- 44 F8.4 km/s HV0 Rest heliocentric velocity
46- 70 A25 --- FileName Name of the spectrum file in subdirectory sp
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Byte-by-byte Description of file (#): sp/*
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Bytes Format Units Label Explanations
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1- 9 F9.4 km/s HV Heliocentric velocity
11- 17 F7.4 --- NFlux Normalised flux
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Byte-by-byte Description of file: listar.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Star Star name
12- 17 A6 --- n_Star Note
19- 37 A19 "datime" Obs.date Observation date
39-146 A108 ---- FileName Name of the spectrum file in subdirectory ar
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Byte-by-byte Description of file (#): ar/*
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Bytes Format Units Label Explanations
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3- 15 E13.8 km/s Vel Velocity in the KI line
18- 30 E13.8 --- NFlux Normalised flux
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Acknowledgements:
Jonathan Smoker, jsmoker(at)eso.org
(End) Jonathan Smoker [ESO Chile], Patricia Vannier [CDS] 07-Aug-2020