<=== observer ===>
"ECAUX",\
"Caux, E.",\
"",\
"CESR",\
"",\
"B.P. 4346",\
"31029",\
"Toulouse Cedex",\
"France",\
" 33    61556689",\
" 33    61556701",\
"caux@cesrva.span.cnes.fr"

<=== proposal ===>
"ISM_IIB", 1, 2,\
{"diffuse interstellar medium","molecular clouds","dust properties",\
"galactic structure"},\
{"LWS consortium","M. Burgdorf","M. Perault"}

<=== title ===>
STUDY OF THE LOW DENSITY COMPONENTS OF THE ISM
THE DIFFUSE MEDIUM IN THE GALACTIC PLANE

<=== abstract ===>
SCIENTIFIC ABSTRACT
This proposal sets out a plan for observation of the diffuse infrared emission
spectrum. It concerns both the Zodiacal light emission and the diffuse Galactic
emission.

These observations have two goals:
1/ to model the diffuse emission elsewhere in the sky to substract it from the
source's emission.
2/ to get information about the chemical and physical properties of the dust
grains embedded in this diffuse medium and about the thermal balance into the
Galaxy, as well as the spatial variation of these properties (with the height
above the plane, and with the galactocentric distance).

One can define three components of the Galactic diffuse medium : the Cirrus,
the HI envelopes of the Giant Molecular Clouds, and the intercloud medium that
is mainly composed of HI gas outside well defined HI clouds. The study of the
two first components concerns other proposals. This proposal only deals with
the last component, the intercloud medium. Another fold of this proposal is the
measure of the Zodiacal light spectrum and its variation with Solar elongation
and Ecliptic latitude.

ISOCAM images, using filters LW 1, 2 and 3, will be taken and will improve the
modeling of the sky around the source, providing information on the
contribution  of discrete sources.

OBSERVATION SUMMARY
Because the infrared diffuse emission is made of several components (Zodiacal,
Galactic and may be Extragalactic), to get the spectrum of the diffuse Galactic
component, we will need first a good knowledge of the zodiacal light spectrum,
and its variation with ecliptic latitude and Solar elongation. In a first step,
we will neglect the maybe existing Extragalactic component.

To get only the emission of the diffuse medium, careful analysis of IRAS maps
has been made in one hand to find the best lines of sight for these
observations, outside emission related to cirrus, molecular clouds as well as
HI clouds.

For the Zodiacal light study, we propose to observe a set of lines of sight
with ISO/LWS to model the intensities and spectral variation of this component.
For the Galactic Diffuse emission, we propose to get first the spectrum of the
local diffuse medium at a few galactic latitude fields, where Galactic emission
related to well-known HI or molecular clouds is minimal. Then, to study the
variation of the diffuse emission spectrum with the galactocentric radius R,
and also with the height above the Galactic plane z, we propose to get full
grating scans for different latitude fields at a few set of Galactic
longitudes,
outside well known strong sources in or near the Galactic disc and well known
nearby high latitude molecular clouds.


<=== scientific_justification ===>
AOTs
The strategy will thus be to take a full grating spectrum for each position.
The exposure times are calculated with AOT LWS01 (full grating scan) with 1
sample per resolution element and with the "fast" scanning mode in order to
achieve signal to noise ratio between 10 and 60 over the whole spectral range.

Zodiacal emission: we propose to observe this emission at ecliptic latitudes
of 0, 15, 30, 45, 60 and 90 degrees for both maximum and minimum solar
elongation.

Galactic emission: we propose to observe the following lines of sight, in
galactic coordinates:
at l = 30d      b = 0, 1, 2, 3, 5 and 10d
                and b = -1, -2, -3, -5 and -10d
at l = 90d      b = 0, 1, 2, 3, 5 and 10d
                and b = -1, -2, -3, -5 and -10d
at l = 165d     b = 0, 1, 2, 3, 5, 10, 30, 60 and 90d
                and b = -1, -2, -3, -5, -10, -30, -60 and -90d

All the planned lines of sight have been selected from careful analysis of the
IRAS maps to be outside the main emission features (cirrus, HI clouds and
molecular clouds).

For Zodiacal Light observations, no coordinates are specified in the source
list, due to the unknown launch date.


LINKED OBSERVATIONS WITH ISOCAM (autumn launch only):
12 arcmin away from the pointed observations with LWS images with ISOCAM are
taken, using filters LW 2 (in parallel mode) and, at a few selected positions,
LW 1 and 3 (as linked observations). The exact positions of these images
around those with LWS will depend on the roll angle of the telescope at the
time the LWS observations will be done, but since they are part of a survey
that will determine the large scale properties of the Galaxy, this kind of
uncertainty does not influence the scientific value of the observations. The
images in three spectral bands will supplement the observations of the CP
proposal "Selected Area Galactic Survey with ISOCAM" (S. Price et al.) and
will therefore be shared between the consortia of this and Dr. Price's
proposal. They will yield an improvement in modeling the point source sky and
will thus provide accurate information on the contribution of discrete sources.

During the pointed observations done in this proposal with LWS, ISOCAM LW 2
(5 - 8.5 um), 6" PFOV, parallel mode observations are automatically obtained
as by-products. In order to supplement them with ISOCAM images in different
filters, some positions of the parallel mode observations are revisited with
ISOCAM LW 3 (12 - 17 um) and LW 1 (4 - 5 um), 6" PFOV, as prime instrument.
As the positions of the ISOCAM parallel mode images depend on the roll angle of
the telescope which is not known in advance, the ISOCAM observations with LW 3
and 1 have to be linked to the pointed LWS observations. The only informations
needed in this procedure from the LWS pointed observations are the exact
positions of the appertaining ISOCAM parallel observations. They will
subsequently be inserted into the target list replacing the current values. In
order to distinguish the names of the ISOCAM parallel mode positions from
those of the LWS prime observations, they have got the suffix "CAM-||" in the
target list. 9 LW 3 and 1 images (in this order) will be taken to match LW 2
observations in parallel mode; only the positions at b = 30 deg, |l| < 10 deg
will be revisited. Many other positions are included in the proposal "Diffuse
infrared emission of the Galaxy" (K. Mattila et al.). Each entry in the target
list takes about 7 minutes with a CAM general observation in two filters; the
spacecraft time for these linked CAM observations is therefore 1.1 hours.


SPACECRAFT TIME SUMMARY
Time distribution for autumn launch targets:
        Team    top 40%         second 30%      last 30%
        LWS:    21124 sec       16028 sec       16448 sec
        SOT:     3960 sec
      total:    25084 sec

Time distribution for spring launch targets:
        Team    top 40%         second 30%      last 30%
        LWS:    21292 sec       15988 sec       16976 sec


<=== autumn_launch_targets ===>
1, "LWS01",1.0,"N","Zod.Light max 00", 0.0, 0.0,2000,0.,0., 656, 0
2, "LWS01",1.0,"N","Zod.Light max 15", 0.0, 0.0,2000,0.,0., 770, 0
3, "LWS01",1.0,"N","Zod.Light max 30", 0.0, 0.0,2000,0.,0.,1264, 0
4, "LWS01",1.0,"N","Zod.Light max 60", 0.0, 0.0,2000,0.,0.,2312, 0
5, "LWS01",1.0,"N","Zod.Light max 90", 0.0, 0.0,2000,0.,0.,2612, 0
6, "LWS01",2.0,"N","Zod.Light min 15", 0.0, 0.0,2000,0.,0.,1628, 0
7, "LWS01",2.0,"N","Zod.Light max 45", 0.0, 0.0,2000,0.,0.,1628, 0
8, "LWS01",3.0,"N","Zod.Light min 00", 0.0, 0.0,2000,0.,0., 878, 0
9, "LWS01",2.0,"N","Zod.Light min 90", 0.0, 0.0,2000,0.,0.,2612, 0
10,"LWS01",3.0,"N","Zod.Light min 30", 0.0, 0.0,2000,0.,0.,1478, 0
11,"LWS01",3.0,"N","Zod.Light min 45", 0.0, 0.0,2000,0.,0.,1628, 0
12,"LWS01",3.0,"N","Zod.Light min 60", 0.0, 0.0,2000,0.,0.,2312, 0
13,"LWS01",1.0,"N","Gal.Light 165+00",04.98440,+41.77014,1950,0.,0., 528, 0
14,"LWS01",1.0,"N","Gal.Light 165+02",05.15789,+42.47594,1950,0.,0., 528, 0
15,"LWS01",1.0,"N","Gal.Light 165+10",05.80930,+46.59722,1950,0.,0., 528, 0
16,"LWS01",1.0,"N","Gal.Light 165+90",12.81361,+27.40000,1950,0.,0.,4196, 0
17,"LWS01",1.0,"N","Gal.Light  90+00",21.07165,+46.82475,1950,0.,0., 580, 0
18,"LWS01",1.0,"N","Gal.Light  90+02",20.96073,+48.59397,1950,0.,0., 528,19
19,"LWS01",1.0,"N","Gal.Light  90+03",20.92176,+49.88872,1950,0.,0., 348, 0
20,"LWS01",1.0,"N","Gal.Light  90+05",20.81231,+51.63856,1950,0.,0., 542, 0
21,"LWS01",1.0,"N","Gal.Light  90+10",20.26306,+53.12381,1950,0.,0., 732, 0
22,"LWS01",1.0,"N","Gal.Light  60+00",19.71196,+24.19167,1950,0.,0., 458, 0
23,"LWS01",1.0,"N","Gal.Light  60+02",19.54413,+24.03419,1950,0.,0., 528, 0
24,"LWS01",1.0,"N","Gal.Light  60+03",19.48796,+24.74958,1950,0.,0., 580, 0
25,"LWS01",1.0,"N","Gal.Light  60+05",19.42884,+27.38681,1950,0.,0., 656, 0
26,"LWS01",1.0,"N","Gal.Light  60+10",18.98755,+27.00261,1950,0.,0., 694, 0
27,"LWS01",1.0,"N","Gal.Light  30+00",18.65869,-04.57192,1950,0.,0., 458,28
28,"LWS01",1.0,"N","Gal.Light  30+01",18.63167,-03.53500,1950,0.,0., 298,29
29,"LWS01",1.0,"N","Gal.Light  30+02",18.57729,-02.58233,1950,0.,0., 298, 0
30,"LWS01",2.0,"N","Gal.Light  30+03",18.56412,-00.86097,1950,0.,0., 458, 0
31,"LWS01",1.0,"N","Gal.Light  30+05",18.41393,-00.79525,1950,0.,0., 488, 0
32,"LWS01",1.0,"N","Gal.Light  30+10",18.17765,+03.25961,1950,0.,0., 542, 0
33,"LWS01",2.0,"N","Gal.Light  30-03",18.96392,-02.27694,1950,0.,0., 478, 0
34,"LWS01",2.0,"N","Gal.Light 165+01",05.11861,+41.30575,1950,0.,0., 528, 0
35,"LWS01",2.0,"N","Gal.Light 165-02",04.79116,+41.17231,1950,0.,0., 542, 0
36,"LWS01",2.0,"N","Gal.Light 165+03",05.19567,+43.64636,1950,0.,0., 542, 0
37,"LWS01",2.0,"N","Gal.Light 165+05",05.44358,+42.85956,1950,0.,0., 542, 0
38,"LWS01",2.0,"N","Gal.Light 165-03",04.72421,+40.53678,1950,0.,0., 528, 0
39,"LWS01",2.0,"N","Gal.Light 165-30",03.32034,+20.38422,1950,0.,0., 508, 0
40,"LWS01",2.0,"N","Gal.Light 165+60",10.94925,+48.00875,1950,0.,0., 694, 0
41,"LWS01",3.0,"N","Gal.Light  90+01",21.02880,+47.84369,1950,0.,0., 542, 0
42,"LWS01",2.0,"N","Gal.Light  90-02",21.38322,+47.48569,1950,0.,0., 656, 0
43,"LWS01",2.0,"N","Gal.Light  90-05",21.52494,+44.72781,1950,0.,0., 694, 0
44,"LWS01",2.0,"N","Gal.Light  90-10",21.93640,+41.85889,1950,0.,0., 694, 0
45,"LWS01",3.0,"N","Gal.Light  60+01",19.66786,+25.16072,1950,0.,0., 488, 0
46,"LWS01",2.0,"N","Gal.Light  60-02",19.80722,+22.35292,1950,0.,0., 528, 0
47,"LWS01",2.0,"N","Gal.Light  60-05",20.05239,+22.22619,1950,0.,0., 618, 0
48,"LWS01",2.0,"N","Gal.Light  60-10",20.29389,+18.27897,1950,0.,0., 656, 0
49,"LWS01",2.0,"N","Gal.Light  30-02",18.91113,-01.63244,1950,0.,0., 458, 0
50,"LWS01",2.0,"N","Gal.Light  30-05",18.94223,-07.26006,1950,0.,0., 508, 0
51,"LWS01",2.0,"N","Gal.Light  30-10",18.33029,-06.93972,1950,0.,0., 528, 0
52,"LWS01",3.0,"N","Gal.Light 165-01",04.97116,+40.24900,1950,0.,0., 528, 0
53,"LWS01",3.0,"N","Gal.Light 165-05",04.63597,+38.66650,1950,0.,0., 528, 0
54,"LWS01",3.0,"N","Gal.Light 165-60",02.22862,-05.27556,1950,0.,0., 542, 0
55,"LWS01",3.0,"N","Gal.Light 165-90",00.81667,-27.40000,1950,0.,0.,4196, 0
56,"LWS01",3.0,"N","Gal.Light  90-01",21.22122,+47.19147,1950,0.,0., 580, 0
57,"LWS01",3.0,"N","Gal.Light  90-03",21.46029,+46.88017,1950,0.,0., 694, 0
58,"LWS01",3.0,"N","Gal.Light  60-01",19.76241,+23.25714,1950,0.,0., 488, 0
59,"LWS01",3.0,"N","Gal.Light  60-03",19.81581,+20.62631,1950,0.,0., 580, 0
60,"LWS01",3.0,"N","Gal.Light  30-01",18.72050,-04.97408,1950,0.,0., 458, 0
61,"CAM01",1.0,"N","G.L.-CAM-||30-05",18.94223,-07.26006,1950,0.,0., 440, 0
62,"CAM01",1.0,"N","G.L.-CAM-||30-03",18.96392,-02.27694,1950,0.,0., 440, 0
63,"CAM01",1.0,"N","G.L.-CAM-||30-02",18.91113,-01.63244,1950,0.,0., 440, 0
64,"CAM01",1.0,"N","G.L.-CAM-||30-01",18.72050,-04.97408,1950,0.,0., 440, 0
65,"CAM01",1.0,"N","G.L.-CAM-||30+00",18.65869,-04.57192,1950,0.,0., 440, 0
66,"CAM01",1.0,"N","G.L.-CAM-||30+01",18.63167,-03.53500,1950,0.,0., 440, 0
67,"CAM01",1.0,"N","G.L.-CAM-||30+02",18.57729,-02.58233,1950,0.,0., 440, 0
68,"CAM01",1.0,"N","G.L.-CAM-||30+03",18.56412,-00.86097,1950,0.,0., 440, 0
69,"CAM01",1.0,"N","G.L.-CAM-||30+05",18.41393,-00.79525,1950,0.,0., 440, 0


<=== spring_launch_targets ===>
1, "LWS01",1.0,"N","Zod.Light max 00", 0.0, 0.0,2000,0.,0., 656, 0
2, "LWS01",1.0,"N","Zod.Light max 15", 0.0, 0.0,2000,0.,0., 770, 0
3, "LWS01",1.0,"N","Zod.Light max 30", 0.0, 0.0,2000,0.,0.,1264, 0
4, "LWS01",1.0,"N","Zod.Light max 60", 0.0, 0.0,2000,0.,0.,2312, 0
5, "LWS01",1.0,"N","Zod.Light max 90", 0.0, 0.0,2000,0.,0.,2612, 0
6, "LWS01",2.0,"N","Zod.Light min 15", 0.0, 0.0,2000,0.,0.,1628, 0
7, "LWS01",2.0,"N","Zod.Light max 45", 0.0, 0.0,2000,0.,0.,1628, 0
8, "LWS01",3.0,"N","Zod.Light min 00", 0.0, 0.0,2000,0.,0., 878, 0
9, "LWS01",2.0,"N","Zod.Light min 90", 0.0, 0.0,2000,0.,0.,2612, 0
10,"LWS01",3.0,"N","Zod.Light min 30", 0.0, 0.0,2000,0.,0.,1478, 0
11,"LWS01",3.0,"N","Zod.Light min 45", 0.0, 0.0,2000,0.,0.,1628, 0
12,"LWS01",3.0,"N","Zod.Light min 60", 0.0, 0.0,2000,0.,0.,2312, 0
13,"LWS01",1.0,"N","Gal.Light 165+00",04.98440,+41.77014,1950,0.,0., 528, 0
14,"LWS01",1.0,"N","Gal.Light 165+02",05.15789,+42.47594,1950,0.,0., 528, 0
15,"LWS01",1.0,"N","Gal.Light 165+10",05.80930,+46.59722,1950,0.,0., 528, 0
16,"LWS01",1.0,"N","Gal.Light 165+30",07.77368,+53.47972,1950,0.,0., 656, 0
17,"LWS01",1.0,"N","Gal.Light 165+90",12.81361,+27.40000,1950,0.,0.,4196, 0
18,"LWS01",1.0,"N","Gal.Light  90+00",21.07165,+46.82475,1950,0.,0., 580, 0
19,"LWS01",1.0,"N","Gal.Light  90+02",20.96073,+48.59397,1950,0.,0., 528,20
20,"LWS01",1.0,"N","Gal.Light  90+03",20.92176,+49.88872,1950,0.,0., 348, 0
21,"LWS01",1.0,"N","Gal.Light  90+05",20.81231,+51.63856,1950,0.,0., 542, 0
22,"LWS01",1.0,"N","Gal.Light  90+10",20.26306,+53.12381,1950,0.,0., 732, 0
23,"LWS01",1.0,"N","Gal.Light  60+00",19.71196,+24.19167,1950,0.,0., 458, 0
24,"LWS01",1.0,"N","Gal.Light  60+02",19.54413,+24.03419,1950,0.,0., 528, 0
25,"LWS01",1.0,"N","Gal.Light  60+03",19.48796,+24.74958,1950,0.,0., 580, 0
26,"LWS01",1.0,"N","Gal.Light  60+05",19.42884,+27.38681,1950,0.,0., 656, 0
27,"LWS01",1.0,"N","Gal.Light  60+10",18.98755,+27.00261,1950,0.,0., 694, 0
28,"LWS01",1.0,"N","Gal.Light  30+00",18.65869,-04.57192,1950,0.,0., 458,29
29,"LWS01",1.0,"N","Gal.Light  30+01",18.63167,-03.53500,1950,0.,0., 298,30
30,"LWS01",1.0,"N","Gal.Light  30+02",18.57729,-02.58233,1950,0.,0., 298, 0
31,"LWS01",2.0,"N","Gal.Light  30+03",18.56412,-00.86097,1950,0.,0., 458, 0
32,"LWS01",2.0,"N","Gal.Light  30+05",18.41393,-00.79525,1950,0.,0., 488, 0
33,"LWS01",1.0,"N","Gal.Light  30+10",18.17765,+03.25961,1950,0.,0., 542, 0
34,"LWS01",2.0,"N","Gal.Light  30-03",18.96392,-02.27694,1950,0.,0., 478, 0
35,"LWS01",3.0,"N","Gal.Light 165+01",05.11861,+41.30575,1950,0.,0., 528, 0
36,"LWS01",2.0,"N","Gal.Light 165-02",04.79116,+41.17231,1950,0.,0., 542, 0
37,"LWS01",3.0,"N","Gal.Light 165+03",05.19567,+43.64636,1950,0.,0., 542, 0
38,"LWS01",2.0,"N","Gal.Light 165+05",05.44358,+42.85956,1950,0.,0., 542, 0
39,"LWS01",2.0,"N","Gal.Light 165-10",05.70644,+09.71986,1950,0.,0., 528, 0
40,"LWS01",2.0,"N","Gal.Light 165-30",03.32034,+20.38422,1950,0.,0., 508, 0
41,"LWS01",2.0,"N","Gal.Light 165+60",10.94925,+48.00875,1950,0.,0., 694, 0
42,"LWS01",2.0,"N","Gal.Light  90+01",21.02880,+47.84369,1950,0.,0., 542, 0
43,"LWS01",2.0,"N","Gal.Light  90-02",21.38322,+47.48569,1950,0.,0., 656, 0
44,"LWS01",2.0,"N","Gal.Light  90-05",21.52494,+44.72781,1950,0.,0., 694, 0
45,"LWS01",2.0,"N","Gal.Light  90-10",21.93640,+41.85889,1950,0.,0., 694, 0
46,"LWS01",3.0,"N","Gal.Light  60+01",19.66786,+25.16072,1950,0.,0., 488, 0
47,"LWS01",2.0,"N","Gal.Light  60-02",19.80722,+22.35292,1950,0.,0., 528, 0
48,"LWS01",2.0,"N","Gal.Light  60-05",20.05239,+22.22619,1950,0.,0., 618, 0
49,"LWS01",2.0,"N","Gal.Light  60-10",20.29389,+18.27897,1950,0.,0., 656, 0
50,"LWS01",2.0,"N","Gal.Light  30-02",18.91113,-01.63244,1950,0.,0., 458, 0
51,"LWS01",2.0,"N","Gal.Light  30-05",18.94223,-07.26006,1950,0.,0., 508, 0
52,"LWS01",2.0,"N","Gal.Light  30-10",18.33029,-06.93972,1950,0.,0., 528, 0
53,"LWS01",3.0,"N","Gal.Light 165-01",04.97116,+40.24900,1950,0.,0., 528, 0
54,"LWS01",3.0,"N","Gal.Light 165-03",04.72421,+40.53678,1950,0.,0., 528, 0
55,"LWS01",3.0,"N","Gal.Light 165-05",04.63597,+38.66650,1950,0.,0., 528, 0
56,"LWS01",3.0,"N","Gal.Light 165-60",02.22862,-05.27556,1950,0.,0., 542, 0
57,"LWS01",3.0,"N","Gal.Light 165-90",00.81667,-27.40000,1950,0.,0.,4196, 0
58,"LWS01",3.0,"N","Gal.Light  90-01",21.22122,+47.19147,1950,0.,0., 580, 0
59,"LWS01",3.0,"N","Gal.Light  90-03",21.46029,+46.88017,1950,0.,0., 694, 0
60,"LWS01",3.0,"N","Gal.Light  60-01",19.76241,+23.25714,1950,0.,0., 488, 0
61,"LWS01",3.0,"N","Gal.Light  60-03",19.81581,+20.62631,1950,0.,0., 580, 0
62,"LWS01",3.0,"N","Gal.Light  30-01",18.72050,-04.97408,1950,0.,0., 458, 0