Bounds on the fine structure constant variability from FeII absorption lines in QSO spectra

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Talk given at ACFC 2007 "Atomic Clocks and Fundamental Constants" conference, Bad Honnef, June 2007, Savely Karshenboim and Ek

Scientific paper

10.1140/epjst/e2008-00818-4

The Single Ion Differential alpha Measurement (SIDAM) method for measuring fine stucture variations (daa)and its figures of merit are illustrated together with the results produced by means of FeII absorption lines of QSO intervening systems. The method provides daa ~= -0.12(+/- 1.79) ppm (parts-per-million) at zabs = 1.15 towards HE 0515--4414 and daa = 5.66(+/-2.67) ppm at zabs= 1.84 towards Q 1101--264, which are so far the most accurate measurements for single systems. SIDAM analysis for 3 systems from the Chand et al. (2004) sample provides inconsistent results which we interpret as due to calibration errors of the Chand et al. data at the level of about 10 ppm. In one system evidence for photo-ionization Doppler shift between MgII and FeII lines is found. This evidence has important bearings on the Many Multiplet method where the signal for daa variability is carried mainly by systems involving MgII absorbers. Some correlations are also found in the Murphy et al. sample which suggest larger errors than previously reported. Thus, we consider unlikely that both the Chand et al. and Murphy et al. datasets could provide an estimate of daa with an accuracy at the level of 1 ppm. A new spectrograph like the ESPRESSO project will be crucial to make progress in the astronomical determination of daa.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Bounds on the fine structure constant variability from FeII absorption lines in QSO spectra 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 Bounds on the fine structure constant variability from FeII absorption lines in QSO spectra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bounds on the fine structure constant variability from FeII absorption lines in QSO spectra will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-508632

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.