J/ApJ/872/55 OI, GeII, KrI & H abundances from HST UV spectra (Jenkins, 2019)
A closer look at some gas-phase depletions in the ISM: trends for O, Ge, and
Kr versus F*, f(H2), and starlight intensity.
Jenkins E.B.
<Astrophys. J., 872, 55 (2019)>
=2019ApJ...872...55J 2019ApJ...872...55J
ADC_Keywords: Abundances; Spectra, ultraviolet; Interstellar medium;
Equivalent widths; Stars, OB
Keywords: dust, extinction ; ISM: abundances ; ISM: atoms ; ultraviolet: ISM
Abstract:
In a survey of archived ultraviolet spectra of 100 stars recorded by
the echelle spectrograph of the Space Telescope Imaging Spectrograph
on the Hubble Space Telescope, we measure the strengths of the weak
absorption features of OI, GeII, and KrI in the interstellar medium.
Our objective is to undertake an investigation that goes beyond
earlier abundance studies to see how these elements are influenced
independently by three different environmental properties: (1) values
of a generalized atomic depletion factor F* due to condensations
onto dust grains (revealed here by the abundances of Mg and Mn
relative to H), (2) the fraction of H atoms in the form of
H2/f(H2), and (3) the ambient intensity I of ultraviolet starlight
relative to an average value in our part of the Galaxy I0. As
expected, the gas-phase abundances of all three elements exhibit
negative partial correlations with F*. The abundances of free O atoms
show significant positive partial correlations with logf(H2) and
log(I/I0), while Ge and Kr exhibit negative partial correlations
with log(I/I0) at marginal levels of significance. After correcting
for these trends, the abundances of O relative to H show no
significant variations with location, except for the already-known
radial gradient of light-element abundances in the Milky Way. A
comparison of Ge and O abundances revealed no significant regional
enhancements or deficiencies of neutron-capture elements relative to
α-process ones.
Description:
A particularly large volume of the STIS echelle spectra on the Hubble
Space Telescope (HST) cover the wavelength region from 1170 to 1372Å,
which includes transitions of OI, MgII, MnII, KrI, and GeII.
These spectra are available from the Mikulsky Archive for Space
Telescopes (MAST).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 100 Stellar and interstellar medium data
table4.dat 97 100 Element measurement outcomes
table5.dat 120 100 H2 and HI measurement outcomes
table7.dat 58 960 HST/STIS measurement outcomes
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/ApJS/93/211 : IUE survey of H I Lyα absorption. I. (Diplas+ 1994)
J/ApJS/176/59 : FUSE survey of OVI in the disk of the Milky Way (Bowen+, 2008)
J/ApJ/700/1299 : Gas-phase element depletions in the ISM (Jenkins, 2009)
J/ApJ/711/1236 : Equivalent width of H2 from FUSE (Jensen+, 2010)
J/ApJ/734/65 : CI radial velocities with HST/STIS (Jenkins+, 2011)
J/A+A/533/A62 : Atomic Data for Neutron-Capture Elements. II (Sterling, 2011)
J/A+A/539/A143 : Nearby B-stars stellar parameters & abundances (Nieva+, 2012)
J/ApJ/764/25 : FUSE spectra analysis of hot subdwarf stars (Jenkins, 2013)
J/AJ/151/143 : Silicon depletion in the interstellar medium (Haris+, 2016)
J/ApJS/230/8 : Compilation of atomic data for heavy elements (Cashman+, 2017)
J/ApJS/236/36 : Ga, Ge, As, Kr, Cd, Sn & Pb column densities (Ritchey+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Name of the target star
13- 18 F6.2 deg GLON [2.2/354] Galactic longitude
20- 25 F6.2 deg GLAT [-50.1/19] Galactic latitude
27- 31 F5.2 kpc Dist [0.12/17] Distance
33 I1 --- r_Dist [1/4] Reference for Dist (1)
35- 39 F5.2 kpc Z [-4.2/0.5] Z coordinate above Galactic Plane
41- 46 F6.3 mag Bmag [5.2/10.1] B-band magnitude
48- 52 F5.2 mag Vmag [4.8/13] V-band magnitude
54- 57 F4.2 mag E(B-V) [0.05/0.6] Color excess
59- 62 F4.2 --- F* [0.15/1.15] Depletion strength F* (2)
64- 67 F4.2 --- e_F* [0.03/0.14] F* uncertainty
69- 72 F4.2 [-] log(I/I0) [0.01/1.2]? Starlight I/I0 (3)
74- 86 A13 --- SpT SIMBAD spectral type
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Note (1): Reference as follows:
1 = Bowen et al. 2008, J/ApJS/176/59
2 = Jenkins 2009, J/ApJ/700/1299
3 = Savage et al. 2017ApJS..232...25S 2017ApJS..232...25S
4 = this paper.
Note (2): Weighted means of the F* values with F* as:
F*=([Xgas/H]-BX)/AX+zX (Equation 6) where X denotes either
Mg or Mn and the coefficients AX, BX, and zX are listed in Table 4
of Jenkins (2009, J/ApJ/700/1299). See Section 4 for further explanations.
Note (3): Logarithm of the intensity of starlight capable of ionizing neutral
carbon for the foreground gas, relative to the Galactic average, as
computed by Jenkins & Tripp (2011, J/ApJ/734/65). See Section 5.
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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- 11 A11 --- Name Name of the star
13 A1 --- l_logNOI Limit flag on logNOI
15- 19 F5.2 [cm-2] logNOI [17.2/18.4]? OI column density
21- 24 F4.2 [cm-2] E_logNOI [0.02/0.2]? Positive 1σ error on logNOI
26- 29 F4.2 [cm-2] e_logNOI [0.02/0.3]? Negative 1σ error on logNOI
31- 35 F5.2 [cm-2] logNMgII [15.4/16.5] MgII column density
37- 40 F4.2 [cm-2] E_logNMgII [0.01/0.1] Positive 1σ error on logNMgII
42- 45 F4.2 [cm-2] e_logNMgII [0.01/0.1] Negative 1σ error on logNMgII
47- 51 F5.2 [cm-2] logNMnII [13.1/14.22] MnII column density
53- 56 F4.2 [cm-2] E_logNMnII [0.01/0.2] Positive 1σ error on logNMnII
58- 61 F4.2 [cm-2] e_logNMnII [0.01/0.3] Negative 1σ error on logNMnII
63 A1 --- l_logNGeII Limit flag on logNGeII
65- 69 F5.2 [cm-2] logNGeII [11.7/13] GeII column density
71- 74 F4.2 [cm-2] E_logNGeII [0.01/0.2]? Positive 1σ error on logNGeII
76- 79 F4.2 [cm-2] e_logNGeII [0.01/0.3]? Negative 1σ error on logNGeII
81 A1 --- l_logNKrI Limit flag on logNKrI
83- 87 F5.2 [cm-2] logNKrI [11.7/13.2] KrI column density
89- 92 F4.2 [cm-2] E_logNKrI [0.03/0.2]? Positive 1σ error on logNKrI
94- 97 F4.2 [cm-2] e_logNKrI [0.03/0.3]? Negative 1σ error on logNKrI
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Name of the star
13- 17 F5.2 [cm-2] logNH2a [17.7/20.7] log of H2 (J=0) column density
19- 22 F4.2 [cm-2] e_logNH2a [0.03/0.5] logNH2a 1.5σ negative error
24- 27 F4.2 [cm-2] E_logNH2a [0.02/0.4] logNH2a 1.5σ positive error
29- 33 F5.2 [cm-2] logNH2b [17.7/20.7] log of H2 (J=1) column density
35- 38 F4.2 [cm-2] e_logNH2b [0.03/0.3] logNH2b 1.5σ negative error
40- 43 F4.2 [cm-2] E_logNH2b [0.03/0.6] logNH2b 1.5σ positive error
45- 49 F5.2 [cm-2] logNH2 [18/21] log of total H2 column density (4)
51- 54 F4.2 [cm-2] e_logNH2 [0.03/0.4] logNH2 1.5σ negative error
56- 59 F4.2 [cm-2] E_logNH2 [0.03/0.4] logNH2 1.5σ positive error
61- 65 F5.2 [cm-2] logNHI [20.5/21.7] log of HI column density
67- 70 F4.2 [cm-2] e_logNHI [0.02/0.3] logNHI 1.5σ negative error
72- 75 F4.2 [cm-2] E_logNHI [0.03/0.2] logNHI 1.5σ positive error
77- 81 F5.2 [cm-2] logNH [20.5/21.8] log of total hydrogen column
density (logNHtot) (4)(5)
83- 86 F4.2 [cm-2] e_logNH [0.02/0.2] logNH 1.5σ negative error
88- 91 F4.2 [cm-2] E_logNH [0.03/0.2] logNH 1.5σ positive error
93- 95 I3 --- T01 [47/203] J=0-1 rotational temperature (4)(6)
97- 99 I3 --- e_T01 [4/113] T01 1.5σ negative error
101-103 I3 --- E_T01 [5/146]? T01 1.5σ positive error
104 A1 --- fET01 [i] i:infinite
106-110 F5.2 [-] logfH2 [-2.5/-0.2] log of fraction of H atoms in
the form of H2, f(H2) (4)(7)
112-115 F4.2 [-] e_logfH2 [0.05/0.4] logfH2 1.5σ negative error
117-120 F4.2 [-] E_logfH2 [0.06/0.4] logfH2 1.5σ positive error
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Note (4): The outcomes in Columns "logNH2", "logNH", "T01", and "logfH2" have
small offsets from the linear combinations of quantities expressed in
other columns in recognition of shifts that are required when
quantities with asymmetric errors are utilized, as described in Section 3.2.
Note (5): Total hydrogen column densities logN(Htot)=log[2N(H2)+N(HI)]
Note (6): The J=0-1 rotational temperature T01=74K/[logN(J=0)-logN(J=1)+0.954]
Note (7): logf(H2)=log[2N(H2)/N(Htot)]
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Name of the star
13 A1 --- f_Name [d] Flag on Name (1)
15 A1 --- Mode Observational mode (2)
17- 19 I3 km/s v1 [-87/13] Lower heliocentric velocity end-point (3)
21- 22 I2 km/s v2 [-4/57] Upper heliocentric velocity end-point (3)
24- 30 A7 --- Line Line identifier (4)
32- 36 F5.1 10-13m EW [-20.8/143.5]? Equivalent width; in mÅ units
38- 41 F4.1 10-13m e_EW [0.4/34.2]? Uncertainty in EW
43 A1 --- l_logN Limit flag on logN
44- 48 F5.2 [cm-2] logN [11.61/21.73] Log of apparent column density
for Line (5)
50- 53 F4.2 [cm-2] E_logN [0.01/0.2]? Upper uncertainty in logN
55- 58 F4.2 [cm-2] e_logN [0.01/0.3]? Lower uncertainty in logN
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Note (1):
d = Not included in the study of element abundance behaviors because no
FUSE observations that revealed H2 column densities are available
for this star. The outcomes for H I and heavy elements are shown for
the benefit of other investigations that could make use of these
results.
Note (2): Code as follows:
H = high resolution mode (E140H);
M = medium resolution mode (E140M).
Note (3): These velocities span the integration intervals for equivalent
widths and apparent column densities.
Note (4): For the heavy elements, the transitions that match the entries here
are listed in Table 3. If the numeral 3 follows an ion, it means that
a correction for line saturation needed to be applied. See Section 3.1
for details. The entry "H I" refers to a direct measurement of the
L-α absorption, whereas for the few cases that needed a
correction for stellar L-α absorption "H I sc" shows the
modified value for logN(H I).
Note (5): See equation 5.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Aug-2020