Observing project: Molecules in absorption at z ~ 1

1
Observing project Molecules in absorption at z
1

• Source PKS1830-21

2
PKS1830-211 z0.88582
Frye et al 97
2 images, Einstein ring But 2 absorbing
systems, one at z0.19 seen in HI
3
Two components, covering each one image of the
source as confirmed by PdB (Wiklind Combes
1998) Slight temporal variability
4
Measuring the continuum of A and B
Possible without resolving the source and
separating the 2images, since the absorption in A
is optically thick
A
A B
5
Monitoring, measure of H0
The single dish (without resolving the 2 images)
can follow the intensity of the two, since they
are absorbing at two V Monitoring during 3 years
(1h per week) gt delay of 245 days, H0 69 12
km/s/Mpc
6
Measure of Tmb (z)
Low excitation (diffuse gas) Tex Tmb The case
for PKS1830-211 Several transitions give the
same result (slightly lower, due to a microlens)
From UV H2 lines Srianand et al 2000
7
Variation of constants
Kaluza-Klein theories, Strings and M-theory,
predict variations of a e2/hc fine structure
constant Heterodyne resolution R106
Method of Alkali doublet of many multiplet Webb
et al (2001) Appears to have a variation, at
high z only Murphy et al (2001) ? a / a
(-0.72 0.18 )10-5