Detection of 21-cm absorption at Z of approximately 1.8 in the quasi-stellar object 1331+170

Details Detection of 21-cm absorption at Z of approximately 1.8 in the quasi-stellar object 1331+170 Detection of 21-cm absorption at Z of approximately 1.8 in the quasi-stellar object 1331+170

Jun 1979

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1979aj.....84..699w&link_type=abstract

Astronomical Journal, vol. 84, June 1979, p. 699-706.

Astronomy and Astrophysics

Astronomy

67

Astronomical Spectroscopy, Electromagnetic Absorption, Neutral Gases, Quasars, Radio Astronomy, Absorption Spectra, Centimeter Waves, Hydrogen Clouds, Lyman Alpha Radiation, Red Shift, Spin Temperature

Scientific paper

The detection of 21-cm absorption by neutral hydrogen in front of the QSO 1331+170 is reported. The line arises at 511.596 + or - 0.005 MHz, corresponding to a redshift, z=1.77642 + or - 0.00002, that is identical, within observational errors, to the previously detected optical redshift of absorption system A. The coincidence between radio and optical redshifts yields the strictest limit ever placed on the variation of certain physical constants over a look-back time comprising at least 65% of the current age of the universe, if the redshifts are cosmological. Comparison with a similar limit pertaining to the z=0.524 absorption event in AO 0235+164 indicates that physical constants in two globally separated regions also coincide. This is evidence for large-scale invariance of physical laws. An analysis of the L-alpha and 21-cm absorption data results in the determination of the spin temperature in a high-z object. If confirmed by future tests, the spin temperature of approximately 1000 K would imply a difference between H I in our Galaxy and in the absorber at z of approximately 1.8.

Affiliated with

Also associated with

No associations

Rating

Detection of 21-cm absorption at Z of approximately 1.8 in the quasi-stellar object 1331+170 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Detection of 21-cm absorption at Z of approximately 1.8 in the quasi-stellar object 1331+170, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection of 21-cm absorption at Z of approximately 1.8 in the quasi-stellar object 1331+170 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1775368