J/MNRAS/454/4013 DIBs in Magellanic Clouds and Milky Way (Bailey+, 2015)
Mapping atomic and diffuse interstellar band absorption across the
Magellanic Clouds and the Milky Way.
Bailey M., van Loon J.T., Sarre P.J., Beckman J.E.
<Mon. Not. R. Astron. Soc., 454, 4013-4026 (2015)>
=2015MNRAS.454.4013B 2015MNRAS.454.4013B (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Magellanic Clouds ; Interstellar medium ;
Equivalent widths
Keywords: ISM: atoms - ISM: lines and bands - ISM: molecules - ISM: structure -
galaxies: ISM - Magellanic Clouds
Abstract:
Diffuse interstellar bands (DIBs) trace warm neutral and weakly
ionized diffuse interstellar medium (ISM). Here we present a
dedicated, high signal-to-noise spectroscopic survey of two of the
strongest DIBs, at 5780 and 5797Å, in optical spectra of 666
early-type stars in the Small and Large Magellanic Clouds, along with
measurements of the atomic NaI D and CaII K lines. The resulting maps
show for the first time the distribution of DIB carriers across large
swathes of galaxies, as well as the foreground Milky Way ISM. We
confirm the association of the 5797Å DIB with neutral gas, and the
5780Å DIB with more translucent gas, generally tracing the
star-forming regions within the Magellanic Clouds. Likewise, the NaI D
line traces the denser ISM whereas the CaII K line traces the more
diffuse, warmer gas. The CaII K line has an additional component at
∼200-220km/s seen towards both Magellanic Clouds; this may be
associated with a pan-Magellanic halo. Both the atomic lines and DIBs
show sub-pc-scale structure in the Galactic foreground absorption; the
5780 and 5797Å DIBs show very little correlation on these small
scales, as do the CaII K and NaI D lines. This suggests that good
correlations between the 5780 and 5797Å DIBs, or between CaII K
and NaI D, arise from the superposition of multiple interstellar
structures. Similarity in behaviour between DIBs and NaI in the Small
Magellanic Cloud (SMC), Large Magellanic Cloud (LMC) and Milky Way
suggests the abundance of DIB carriers scales in proportion to
metallicity.
Description:
The observations were carried out with the 3.9-m Anglo-Australian
Telescope (AAT) at Siding Spring, Australia, during 2011 November
3-6 (programmes ATAC/10B/51 and AAT/11B/17; PI: J.Th. van Loon). The
two-degree field (2dF) 400-fibre positioning system was used in
conjunction with the AAΩ spectrograph mounted at the Coude
focus, benefitting from a wide-field corrector and an atmospheric
dispersion compensator.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 80 657 List of observed targets
table3.dat 211 329 Spectral line measurements for SMC sightlines
table4.dat 227 328 Spectral line measurements for LMC sightlines
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See also:
J/AJ/123/855 : Magellanic Clouds Photometric Survey: the SMC (Zaritsky+, 2002)
J/AJ/128/1606 : Magellanic Clouds Photometric Survey: the LMC (Zaritsky+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Cluster [SMC LMC] Cluster
5- 8 I4 --- Seq Sequential number
10 I1 h RAh Right ascension (J2000) (1)
12- 13 I2 min RAm Right ascension (J2000) (1)
15- 19 F5.2 s RAs Right ascension (J2000) (1)
21 A1 --- DE- Declination sign (J2000) (1)
22- 23 I2 deg DEd Declination (J2000) (1)
25- 26 I2 arcmin DEm Declination (J2000) (1)
28- 31 F4.1 arcsec DEs Declination (J2000) (1)
33- 41 F9.5 deg GLON Galactic longitude (1)
43- 51 F9.5 deg GLAT Galactic latitude (1)
53- 57 F5.2 mag Bmag B magnitude (2)
59- 63 F5.2 mag Vmag B magnitude (2)
65- 80 A16 --- SpType MK spectral type (3)
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Note (1): Both equatorial and Galactic coordinates are given as the latter
are useful in interpreting the foreground absorption.
Note (2): B- and V-band photometries are from Zaritsky et al. (2002,
Cat. J/AJ/123/855 for SMC, 2004, Cat. J/AJ/128/1606 for LMC).
Note (3): Spectral types and luminosity classes are based on a literature search
and only available for 174 SMC and 61 LMC targets (see Appendix A).
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Seq Sequential number
6- 10 F5.3 0.1nm EWCaIIKbi CaII K blue equivalent width, SMC, internal
12- 16 F5.3 0.1nm e_EWCaIIKbi rms uncertainty on EWCaIIKbi, SMC, internal
18- 22 F5.1 --- RCaIIKbi Ratio EWCaIIKb/e_EWCaIIKbi, SMC, internal
24- 28 F5.3 0.1nm EWCaIIKri CaII K red equivalent width, SMC, internal
30- 34 F5.3 0.1nm e_EWCaIIKri rms uncertainty on EWCaIIKri, SMC, internal
36- 40 F5.1 --- RCaIIKri Ratio EWCaIIKri/e_EWCaIIKri, SMC, internal
42- 46 F5.3 0.1nm EW5780i 5780Å DIB equivalent width, SMC, internal
48- 52 F5.3 0.1nm e_EW5780i rms uncertainty on EW5780i, SMC, internal
54- 57 F4.1 --- R5780i Ratio EW5780i/e_EW5780i, SMC, internal
59- 63 F5.3 0.1nm EW5797i 5797Å DIB equivalent width, SMC, internal
65- 69 F5.3 0.1nm e_EW5797i rms uncertainty on 5797i, SMC, internal
71- 74 F4.1 --- R5797i Ratio EW5797i/e_EW5797i, SMC, internal
76- 80 F5.3 0.1nm EWNaID2i NaID2 equivalent width, SMC, internal
82- 86 F5.3 0.1nm EWNaID1i NaID1 equivalent width, SMC, internal
88- 92 F5.3 0.1nm e_EWNaID2i rms uncertainty on NaID2, SMC, internal
94- 98 F5.3 0.1nm e_EWNaID1i rms uncertainty on EWNaID1i, SMC, internal
100-104 F5.1 --- RNaID2i Ratio EWNaID2i/e_EWNaID2i, SMC, internal
106-110 F5.1 --- RNaID1i Ratio EWNaID1i/e_EWNaID1i, SMC, internal
112 I1 --- fCaIIKbi [0/1] Detection flag for CaIIKb,
SMC, internal (G1)
114 I1 --- f5780i [0/1] Detection flag for 5780,
SMC, internal (G1)
116 I1 --- f5797i [0/1] Detection flag for 5797,
SMC, internal (G1)
118 I1 --- fNaIDi [0/1] Detection flag for NaID,
SMC, internal (G1)
120-124 F5.3 0.1nm EWCaIIKG CaII K equivalent width,
Galactic in SMC direction
126-130 F5.3 0.1nm e_EWCaIIKG rms uncertainty on EWCaIIKG,
Galactic in SMC direction
132-135 F4.1 --- RCaIIKG Ratio EWCaIIKG/e_EWCaIIKG,
Galactic in SMC direction
137-141 F5.3 0.1nm EW5780G 5780Å DIB equivalent width,
Galactic in SMC direction
143-147 F5.3 0.1nm e_EW5780G rms uncertainty on EW5780G,
Galactic in SMC direction
149-152 F4.1 --- R5780G Ratio EW5780G/e_EW5780G,
Galactic in SMC direction
154-158 F5.3 0.1nm EW5797G 5797Å DIB equivalent width,
Galactic in SMC direction
160-164 F5.3 0.1nm e_EW5797G rms uncertainty on EW5797G,
Galactic in SMC direction
166-169 F4.1 --- R5797G Ratio EW5797G/e_EW5797G,
Galactic in SMC direction
171-175 F5.3 0.1nm EWNaID2G NaID2 equivalent width,
Galactic in SMC direction
177-181 F5.3 0.1nm EWNaID1G NaID1 equivalent width,
Galactic in SMC direction
183-187 F5.3 0.1nm e_EWNaID2G rms uncertainty on NaID2G,
Galactic in SMC direction
189-193 F5.3 0.1nm e_EWNaID1G rms uncertainty on EWNaID1G,
Galactic in SMC direction
195-198 F4.1 --- RNaID2G Ratio EWNaID2G/e_EWNaID2G,
Galactic in SMC direction
200-203 F4.1 --- RNaID1G Ratio EWNaID1G/e_EWNaID1G,
Galactic in SMC direction
205 I1 --- fCaIIKG [0/1] Detection flag for CaIIK,
Galactic in SMC direction (G1)
207 I1 --- f5780G [0/1] Detection flag for 5780,
Galactic in SMC direction (G1)
209 I1 --- f5797G [0/1] Detection flag for 5797,
Galactic in SMC direction (G1)
211 I1 --- fNaIDG [0/1] Detection flag for NaID,
Galactic in SMC direction (G1)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Seq Sequential number
6- 10 F5.3 0.1nm EWCaIIKbi CaII K blue equivalent width, LMC, internal
12- 16 F5.3 0.1nm e_EWCaIIKbi rms uncertainty on EWCaIIKbi, LMC, internal
18- 21 F4.1 --- RCaIIKbi Ratio EWCaIIKbi/e_EWCaIIKbi, LMC, internal
23- 27 F5.3 0.1nm EWCaIIKri CaII K red equivalent width, LMC, internal
29- 33 F5.3 0.1nm e_EWCaIIKri rms uncertainty on EWCaIIKri, LMC, internal
35- 39 F5.1 --- RCaIIKri Ratio EWCaIIKri/e_EWCaIIKri, LMC, internal
41- 45 F5.3 0.1nm EW5780i 5780Å DIB equivalent width, LMC, internal
47- 51 F5.3 0.1nm e_EW5780i rms uncertainty on EW5780i, LMC, internal
53- 57 F5.1 --- R5780i Ratio EW5780i/e_EW5780i, LMC, internal
59- 63 F5.3 0.1nm EW5797i 5797Å DIB equivalent width, LMC, internal
65- 69 F5.3 0.1nm e_EW5797i rms uncertainty on 5797i, LMC, internal
71- 74 F4.1 --- R5797i Ratio EW5797i/e_EW5797i, LMC, internal
76- 80 F5.3 0.1nm EWNaID2i NaID2 equivalent width, LMC, internal
82- 86 F5.3 0.1nm EWNaID1i NaID1 equivalent width, LMC, internal
88- 92 F5.3 0.1nm e_EWNaID2i rms uncertainty on NaID2, LMC, internal
94- 98 F5.3 0.1nm e_EWNaID1i rms uncertainty on EWNaID1, LMC, internal
100-103 F4.1 --- RNaID2i Ratio EWNaID2/e_EWNaID2, LMC, internal
105-109 F5.1 --- RNaID1i Ratio EWNaID1/e_EWNaID1, LMC, internal
111 I1 --- fCaIIKbi [0/1] Detection flag for CaIIKb,
LMC, internal (G1)
113 I1 --- f5780i [0/1] Detection flag for 5780,
LMC, internal (G1)
115 I1 --- f5797i [0/1] Detection flag for 5797,
LMC, internal (G1)
117 I1 --- fNaIDi [0/1] Detection flag for NaID,
LMC, internal (G1)
119-123 F5.3 0.1nm EWCaIIKbG CaII K blue equivalent width,
Galactic in LMC direction
125-129 F5.3 0.1nm e_EWCaIIKbG rms uncertainty on EWCaIIKbG,
Galactic in LMC direction
131-134 F4.1 --- RCaIIKbG Ratio EWCaIIKbG/e_EWCaIIKbG,
Galactic in LMC direction
136-140 F5.3 0.1nm EWCaIIKrG CaII K red equivalent width, LMC, internal
142-146 F5.3 0.1nm e_EWCaIIKrG rms uncertainty on EWCaIIKrG, LMC, internal
148-151 F4.1 --- RCaIIKrG Ratio EWCaIIKrG/e_EWCaIIKrG, LMC, internal
153-157 F5.3 0.1nm EW5780G 5780Å DIB equivalent width,
Galactic in LMC direction
159-163 F5.3 0.1nm e_EW5780G rms uncertainty on EW5780G,
Galactic in LMC direction
165-168 F4.1 --- R5780G Ratio EW5780G/e_EW5780G,
Galactic in LMC direction
170-174 F5.3 0.1nm EW5797G 5797Å DIB equivalent width,
Galactic in LMC direction
176-180 F5.3 0.1nm e_EW5797G rms uncertainty on EW5797G,
Galactic in LMC direction
182-185 F4.1 --- R5797G Ratio EW5797/e_EW5797,
Galactic in LMC direction
187-191 F5.3 0.1nm EWNaID2G NaID2 equivalent width,
Galactic in LMC direction
193-197 F5.3 0.1nm EWNaID1G NaID1 equivalent width,
Galactic in LMC direction
199-203 F5.3 0.1nm e_EWNaID2G rms uncertainty on NaID2,
Galactic in LMC direction
205-209 F5.3 0.1nm e_EWNaID1G rms uncertainty on EWNaID1G,
Galactic in LMC direction
211-214 F4.1 --- RNaID2G Ratio EWNaID2G/e_EWNaID2G,
Galactic in LMC direction
216-219 F4.1 --- RNaID1G Ratio EWNaID1G/e_EWNaID1G,
Galactic in LMC direction
221 I1 --- fCaIIKbG [0/1] Detection flag for CaIIKbG,
Galactic in LMC direction (G1)
223 I1 --- f5780G [0/1] Detection flag for 5780,
Galactic in LMC direction (G1)
225 I1 --- f5797G [0/1] Detection flag for 5797,
Galactic in LMC direction (G1)
227 I1 --- fNaIDG [0/1] Detection flag for NaID,
Galactic in LMC direction (G1)
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Global notes:
Note (G1): Detection flag as follows:
1 = detection
0 = non-detection
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Acknowledgements:
Jacco Th. van Loon, j.t.van.loon(at)keele.ac.uk
(End) Patricia Vannier [CDS] 18-May-2016