Astronomical applications of survival analysis

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6231382

Isobe, Takashi

Astronomers often observe a sample of objects in search of statistical results such as luminosity functions and correlations. Statistical techniques are discussed which are applicable to a sample in which a portion of the variables are not detected, e.g., when upper limits are present in the variables. An extensive field of statistics called survival analysis addresses this problem. Several survival analysis techniques most useful to astronomical data analysis are presented. Using Monte Carlo simulations, the performance and accuracy of survival analysis in astronomical situations is tested. The simulations show that survival analysis is reliable in the search for correlations between luminosities at different bands. As an application of univariate survival analysis, a study is presented of continuum radiation from active galactic nuclei (AGNs). Several previous studies with correct statistical methods and large databases are confirmed: Radio selected quasars have two different emission mechanisms in the x ray band: BL Lac objects appear to be special cases of the radio selected quasars; some compact radio sources show the possibility of Synchritron-Self-Conpton in the optical band.

• Research Organization: Pennsylvania State Univ., University Park, PA (USA). Davey Lab.
• OSTI ID: 6231382
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BL LACERTAE OBJECTS
COSMIC DUST
COSMIC RADIO SOURCES
DATA
DATA ANALYSIS
DUSTS
ELECTROMAGNETIC RADIATION
GALAXY NUCLEI
INFORMATION
INFRARED SPECTRA
IONIZING RADIATIONS
LUMINOSITY
MONTE CARLO METHOD
NUMERICAL DATA
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
QUASARS
RADIATIONS
SIMULATION
SPECTRA
THEORETICAL DATA
X RADIATION