May 11th, 2008| 10:42 pm | Posted by hlee

I think I have to review spatial statistics in astronomy, focusing on tessellation (void structure), point process (expanding 2 (3) point correlation function), and marked point process (spatial distribution of hardness ratios of X-ray distant sources, different types of galaxies -not only morphological differences but other marks such as absolute magnitudes and existence of particular features). When? Someday…

In addition to Bayesian methodologies, like this week’s astro-ph, studies on characterizing empirical spatial distributions of voids and galaxies frequently appear, which I believe can be enriched further with the ideas from stochastic geometry and spatial statistics. Click for what was appeared in arXiv this week. Continue reading ‘[ArXiv] 1st week, May 2008’ »

Tags:

Classification,

covariance,

FARIMA,

Fisher information,

GL,

GRB,

Levy,

light curve,

limb darkening,

ML,

Pareto distribution,

quasars,

solar flare,

standard candle,

tessellation,

time series,

VO,

void Category:

arXiv,

MCMC,

Uncertainty |

1 Comment
Apr 11th, 2008| 02:21 am | Posted by hlee

Markov chain Monte Carlo became the most frequent and stable statistical application in astronomy. It will be useful collecting tutorials from both professions. Continue reading ‘[ArXiv] 2nd week, Apr. 2008’ »

Tags:

Classification,

GRB,

Hubble constant,

K-S test,

kurtosis,

mask,

maximum likelihood,

SDSS,

skewness,

Solar Oscillation,

Vicent Martinez Category:

arXiv,

Bayesian,

MCMC,

Methods,

Stat |

3 Comments
Feb 1st, 2008| 02:01 pm | Posted by hlee

Some statistics papers were listed at the top, of which topics would interest some slog subscribers.

Continue reading ‘[ArXiv] 5th week, Jan. 2008’ »

Jan 11th, 2008| 03:44 pm | Posted by hlee

It is notable that there’s an astronomy paper contains **AIC, BIC**, and **Bayesian evidence** in the title. The topic of the paper, unexceptionally, is cosmology like other astronomy papers discussed these (statistical) information criteria (I only found a couple of papers on model selection applied to astronomical data analysis without articulating CMB stuffs. Note that I exclude Bayes factor for the model selection purpose).

To find the paper or other interesting ones, click Continue reading ‘[ArXiv] 2nd week, Jan. 2007’ »

Tags:

AIC,

Bayesian evidence,

BIC,

catalog,

Classification,

CMB,

confidence interval,

consistency,

correlation,

GRB,

information criterion,

Model Selection,

SDSS,

test,

WMAP Category:

arXiv |

Comment
Aug 14th, 2007| 12:47 pm | Posted by hlee

From arxiv/astro-ph:0708.1510v1

**Connecting GRBs and galaxies: the probability of chance coincidence** by Cobb and Bailyn

Without an optical afterglow, a galaxy within the 2 arc second error region of a GRB x-ray afterglow is identified as a host galaxy; however confusion can rise due to the facts that 1. the edge of a galaxy is diffused, 2. multiple sources could exist within 2 arc second error region, 3.the distance between the galaxy and the x-ray afterglow is measured by projection, and 4. lensing causes increase of brightness and position shifts. In this paper, the authors “investigated the fields of 72 GRBs in order to examine the general issue of associations between GRBs and host galaxies.”

Continue reading ‘[ArXiv] GRB host galaxies, Aug. 10, 2007’ »

Tags:

afterglow,

false discovery,

GRB,

host galaxy,

lensing,

source matching Category:

arXiv,

Data Processing,

Galaxies,

gamma-ray,

Objects,

Uncertainty |

Comment
Jul 25th, 2007| 03:22 am | Posted by hlee

From arxiv/astro-ph:0705.4020v2

**Statistical Evidence for Three classes of Gamma-ray Bursts** by T. Chattopadhyay et. al.

In general, gamma-ray bursts (GRBs) are classified into two groups: long (>2 sec) and short (<2 sec) duration bursts. Nonetheless, there have been some studies including arxiv/astro-ph:0705.4020v2 that statistically proved the optimal existence of 3 clusters. The pioneer work of GRB clusterings was based on hierarchical clustering methods by Mukerjee et. al.(Three Types of Gamma-Ray Bursts)

Continue reading ‘[ArXiv] Three Classes of GRBs, July 21, 2007’ »

Jul 16th, 2007| 12:15 pm | Posted by hlee

From arxiv/astro-ph:0707.1900v1

** The complete catalogue of gamma-ray bursts observed by the Wide Field Cameras on board BeppoSAX ** by Vetere, et.al.

This paper intend to publicize the largest data set of Gamma Ray Burst (GRB) X-ray afterglows (right curves after the event), which is available from http://www.asdc.asi.it. It is claimed to be a complete on-line catalog of GRB observed by two wide-Field Cameras on board BeppoSAX (Click for its Wiki) in the period of 1996-2002. It is comprised with 77 bursts and 56 GRBs with Xray light curves, covering the energy range 40-700keV. A brief introduction to the instrument, data reduction, and catalog description is given.

Tags:

afterglow,

BeppoSAX,

catalog,

GRB,

light curve Category:

arXiv,

Data Processing,

gamma-ray,

Objects,

Spectral,

Timing,

X-ray |

1 Comment