J/A+A/585/A12 Nearby early-type stars spectroscopic survey (Bailey+, 2016)
Probing the Local Bubble with diffuse interstellar bands.
I. Project overview and Southern hemisphere survey.
Bailey M., van Loon J.T., Farhang A., Javadi A., Khosroshahi H.G.,
Sarre P.J., Smith K.T.
<Astron. Astrophys. 585, A12 (2016)>
=2016A&A...585A..12B 2016A&A...585A..12B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Stars, late-type ; Equivalent widths
Keywords: ISM: atoms - ISM: bubbles - ISM: lines and bands - ISM: molecules -
ISM: structure - local interstellar matter
Abstract:
We have conducted a high signal-to-noise spectroscopic survey of 670
nearby early-type stars, to map Diffuse Interstellar Band (DIB)
absorption in and around the Local Bubble. The project started with a
Southern hemisphere survey conducted at the European Southern
Observatory's New Technology Telescope and has since been extended to
an all-sky survey using the Isaac Newton Telescope. In this first
paper in the series, we introduce the overall project and present the
results from the Southern hemisphere survey. We make available a
catalogue of equivalent-width measurements of the DIBs at 5780, 5797,
5850, 6196, 6203, 6270, 6283 & 6614Å, the interstellar NaI D lines
at 5890 & 5896Å, and the stellar HeI line at 5876Å. We find that
the 5780Å DIB is relatively strong throughout, as compared to the
5797Å DIB, but especially within the Local Bubble and at the
interface with more neutral medium. The 6203Å DIB shows a similar
behaviour, but with respect to the 6196Å DIB. Some nearby stars
show surprisingly strong DIBs whereas some distant stars show very
weak DIBs, indicating small-scale structure within as well as outside
the Local Bubble. The sight-lines with non-detections trace the extent
of the Local Bubble especially clearly, and show it opening out into
the Halo. The Local Bubble has a wall which is in contact with hot gas
and/or a harsh interstellar radiation field. That wall is perforated
though, causing leakage of radiation and possibly hot gas. On the
other hand, compact self-shielded cloudlets are present much closer to
the Sun, probably within the Local Bubble itself. As for the carriers
of the DIBs, our observations confirm the notion that these are large
molecules, whose differences in behaviour are mainly governed by their
differing resilience and/or electrical charge, with more subtle
differences possibly related to varying excitation.
Description:
We obtained long-slit spectroscopic data using the 3.5m New Technology
Telescope (NTT) at the European Southern Observatory, La Silla, Chile.
The observations were performed in visitor mode on the nights of 21-23
March 2011 and 15-17 August 2011 (ESO programme 087.C-0405(A+B); PI:
M.Bailey) and 19-22 August 2012 (ESO programme 0.89.C-0797; PI:
M.Bailey).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 110 238 Catalogue of observed stars
table3.dat 230 238 Spectral line measurements
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [HD]
3- 8 I6 --- HD Star number from Henry Draper catalogue
10- 11 I2 h RAh Right ascension (J2000)
13- 14 I2 min RAm Right ascension (J2000)
16- 20 F5.2 s RAs Right ascension (J2000)
22 A1 --- DE- Declination sign (J2000)
23- 24 I2 deg DEd Declination (J2000)
26- 27 I2 arcmin DEm Declination (J2000)
29- 32 F4.1 arcsec DEs Declination (J2000)
34- 41 F8.4 deg GLON Galactic longitude
43- 50 F8.4 deg GLAT Galactic latitude
52- 58 F7.2 mas/yr pmRA Proper motion along RA
60- 63 F4.2 mas/yr e_pmRA rms uncertainty on pmRA
65- 71 F7.2 mas/yr pmDE Proper motion along DE
73- 76 F4.2 mas/yr e_pmDE rms uncertainty on pmDE
78- 82 F5.2 mas plx Parallax
84- 87 F4.2 mas e_plx rms uncertainty on plx
89- 93 F5.1 pc Dist Distance
95- 98 F4.2 mag Vmag Visual magnitude
100-110 A11 --- SpType MK Spectral type
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [HD]
3- 8 I6 --- HD Star number from Henry Draper catalogue
10- 14 F5.3 0.1nm EW5780 Equivalent width DIB lambda5780
16- 21 F6.4 0.1nm e_EW5780 Equivalent width uncertainty DIB lambda5780
23- 26 F4.1 --- R5780 EW/e_EW DIB lambda5780 ratio
28- 32 F5.3 0.1nm EW5797 Equivalent width DIB lambda5797
34- 39 F6.4 0.1nm e_EW5797 Equivalent width uncertainty DIB lambda5797
41- 44 F4.1 --- R5797 EW/e_EW DIB lambda5797 ratio
46- 50 F5.3 0.1nm EW5850 Equivalent width DIB lambda5850
52- 57 F6.4 0.1nm e_EW5850 Equivalent width uncertainty DIB lambda5850
59- 62 F4.1 --- R5850 EW/e_EW DIB lambda5850 ratio
64- 68 F5.3 0.1nm EWHeID3 Equivalent width HeI D3
70- 75 F6.4 0.1nm e_EWHeID3 Equivalent width uncertainty HeI D3
77- 81 F5.1 --- RHeID3 EW/e_EW HeI D3 ratio
83- 87 F5.3 0.1nm EWNaID2 Equivalent width NaI D2
89- 94 F6.4 0.1nm e_EWNaID2 Equivalent width uncertainty NaI D2
96-100 F5.3 0.1nm EWNaID1 Equivalent width NaI D1
102-107 F6.4 0.1nm e_EWNaID1 Equivalent width uncertainty NaI D1
109-112 F4.1 --- RNaID2 EW/e_EW NaI D2 ratio
114-117 F4.1 --- RNaID1 EW/e_EW NaI D1 ratio
119-123 F5.3 0.1nm EW6116 Equivalent width DIB lambda6196
125-130 F6.4 0.1nm e_EW6116 Equivalent width uncertainty DIB lambda6196
132-136 F5.3 0.1nm EW6203 Equivalent width DIB lambda6203
138-143 F6.4 0.1nm e_EW6203 Equivalent width uncertainty DIB lambda6203
145-147 F3.1 --- R6196 EW/e_EW DIB lambda6196 ratio
149-152 F4.1 --- R6203 EW/e_EW DIB lambda6203 ratio
154-158 F5.3 0.1nm EW6270 Equivalent width DIB lambda6270
160-165 F6.4 0.1nm e_EW6270 Equivalent width uncertainty DIB lambda6270
167-170 F4.1 --- R6270 EW/e_EW DIB lambda6270 ratio
172-176 F5.3 0.1nm EW6283 Equivalent width DIB lambda6283
178-183 F6.4 0.1nm e_EW6283 Equivalent width uncertainty DIB lambda6283
185-188 F4.1 --- R6283 EW/e_EW DIB lambda6283 ratio
190-194 F5.3 0.1nm EW6614 Equivalent width DIB lambda6614
196-201 F6.4 0.1nm e_EW6614 Equivalent width uncertainty DIB lambda6614
203-206 F4.1 --- R6614 EW/e_EW DIB lambda6614 ratio
208 I1 --- f5780 [0/2] Flag for DIB lambda5780 (1)
210 I1 --- f5797 [0/2] Flag for DIB lambda5797 (1)
212 I1 --- f5850 [0/2] Flag for DIB lambda5850 (1)
214 I1 --- fHeID3 [0/2] Flag for HeI D3 (1)
216 I1 --- fNaID2 [0/2] Flag for NaI D2 (1)
218 I1 --- fNaID1 [0/2] Flag for NaI D1 (1)
220 I1 --- fNaDip [0/2] Flag for Na dip (1)
222 I1 --- f6196 [0/2] Flag for DIB lambda6196 (1)
224 I1 --- f6203 [0/2] Flag for DIB lambda6203 (1)
226 I1 --- f6270 [0/2] Flag for DIB lambda6270 (1)
228 I1 --- f6283 [0/2] Flag for DIB lambda6283 (1)
230 I1 --- f6614 [0/2] Flag for DIB lambda6614 (1)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
1 = detection
0 = non-detection
2 = dubious (excluded from further analysis)
--------------------------------------------------------------------------------
Acknowledgements:
Jacco Th. van Loon, j.t.van.loon(at)keele.ac.uk
(End) Patricia Vannier [CDS] 15-Oct-2015