New Cosmological Structures on Medium Angular Scales Detected with the Tenerife Experiments

We present observations at 10 and 15 GHz taken with the Tenerife experimentsin a band of the sky at Dec.=+35 degrees. These experiments are sensitive tomultipoles in the range l=10-30. The sensitivity per beam is 56 and 20 microKfor the 10 and the 15 GHz data, respectively. After subtraction of theprediction of known radio-sources, the analysis of the data at 15 GHz at highGalactic latitude shows the presence of a signal with amplitude Delta Trms ~ 32microK. In the case of a Harrison-Zeldovich spectrum for the primordialfluctuations, a likelihood analysis shows that this signal corresponds to aquadrupole amplitude Q_rms-ps=20.1+7.1-5.4 microK, in agreement with ourprevious results at Dec.+=40 degrees and with the results of the COBE DMR.There is clear evidence for the presence of individual features in the RA range190 degrees to 250 degrees with a peak to peak amplitude of ~110 microK. Apreliminary comparison between our results and COBE DMR predictions for theTenerife experiments clearly indicates the presence of individual featurescommon to both. The constancy in amplitude over such a large range in frequency(10-90 GHz) is strongly indicative of an intrinsic cosmological origin forthese structures.Comment: ApJ Letters accepted, 13 pages Latex (uses AASTEX) and 4 encapsulated postscript figures