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M. Limon

Publications and source records attributed to M. Limon.

75 records · Page 5Linked to original sources

An Efficient Technique for making maps from Observations of the Cosmic Microwave Background Radiation

We describe a new technique for turning scans of the microwave sky into intensity maps. The technique is based on a Fourier series analysis and is inspired by the lock-in deconvolution used in experiments which typically sweep the sky continuously. We test the technique on computer generated microwave skies and compare it to the more standard map making technique based on linear algebra. We find that our technique is much faster than the usual technique and, in addition, does not suffer from the problem of memory limitations. Lastly we demonstrate that the technique works under real experimental conditions using observations of the moon.

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The GEM Project: an International Collaboration to Survey Galactic Radiation Emission

The GEM (Galactic Emission Mapping) project is an international collaboration established with the aim of surveying the full sky at long wavelengths with a multi-frequency radio telescope. A total of 745 hours of observation at 408 MHz were completed from an Equatorial site in Colombia. The observations cover the celestial band $0^h < α< 24^h$, and $-24^{\circ} \ 22^{\prime} < δ< +35^{\circ} \ 37^{\prime}$. Preliminary results of this partial survey will be discussed. A review of the instrumental setup and a $\sim 10^{\circ}$ resolution sky map at 408 MHz is presented.

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COBE Observations of the Microwave Counterparts of Gamma Ray Bursts

We have used the data from the COBE satellite to search for delayed microwave emission (31 - 90 GHz) from Gamma Ray Bursts (GRBs). The large $7^\circ$ beam of COBE is well matched to the large positional uncertainties in the GRB locations, although it also means that fluxes from (point source) GRB objects will be diluted. In view of this we are doing a statistical search of the GRBs which occurred during the currently released COBE DMR data (years 1990 and 1991), which overlap $\sim 200$ GRBs recorded by GRO. Here we concentrate on just the top 10 GRBs (in peak counts/second). We obtain the limits on the emission by comparing the COBE fluxes before and after the GRB at the GRB location. Since it is thought that the microwave emission should lag the GRB event, we have searched the GRB position for emission in the few months following the GRB occurrence.

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