RUI:  Low-Frequency Studies of Active Extragalactic Radio   Sources
{'Code': '03020400', 'Directorate': {'Abbreviation': 'MPS', 'LongName': 'Direct For Mathematical & Physical Scien'}, 'Division': {'Abbreviation': 'AST', 'LongName': 'Division Of Astronomical Sciences'}}
{'SignBlockName': 'Millissa J. Evans', 'PO_EMAI': None, 'PO_PHON': None}
The objective of this project is to document the low frequency                  (frequency less than 1 GHz) characteristics of variable                         extragalactic radio sources.  These data will be compared with                  the predictions of the various mechanisms which have been proposed              for this activity.  These mechanisms can be divided into:                                                                                                       a)  Intrinsic variability of a relativistically evolving source,                     and                                                                        b)  Extrinsic variability due to scattering or absorption in the                     intervening medium.                                                                                                                                        In order to decide between the hypotheses, observations will                    be carried out to:                                                                                                                                              a)  Continue with the periodic measurements of the                                   flux density of radio sources at low frequencies (318 MHz                       and 430 MHz),                                                              b)  Obtain high resolution images of the sources at low                              frequencies (327 MHz) using Very Long Baseline Interferometry                   (VLBI), and                                                                c)  Obtain low frequency (327 MHz) images of these sources at the                    Very Large Array (VLA).                                                                                                                                    The data base will be augmented by data from a collaboration with               other groups working at radio and optical wavelengths.                                                                                                          The participation of undergraduate and graduate students in this                project, which involves international cooperation and the use of                modern and sophisticated techniques, represents for them                        challenging and rewarding opportunities.
{'FirstName': 'Jose', 'LastName': 'Nieves', 'PI_MID_INIT': 'F', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Jose F Nieves', 'EmailAddress': 'nieves@ltp.uprrp.edu', 'NSF_ID': '000479580', 'StartDate': '05/01/1988', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'University of Puerto Rico-Rio Piedras', 'CityName': 'SAN JUAN', 'ZipCode': '00931', 'PhoneNumber': '7877634949', 'StreetAddress': '39 PONCE DE LEON AVE', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Puerto Rico', 'StateCode': 'PR', 'CONGRESSDISTRICT': '00', 'CONGRESS_DISTRICT_ORG': 'PR00', 'ORG_UEI_NUM': 'Q3LLLDFHPNL3', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF PUERTO RICO', 'ORG_PRNT_UEI_NUM': None}
{'Name': None, 'CityName': None, 'StateCode': None, 'ZipCode': None, 'StreetAddress': None, 'CountryCode': None, 'CountryName': None, 'StateName': None, 'CountryFlag': None, 'CONGRESSDISTRICT': None, 'CONGRESS_DISTRICT_PERF': '""'}
{'Code': '912000', 'Text': 'CROSS-DIRECTORATE PROGRAMS'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1987&All=true', 'xml': '8715532.xml'}