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196 Research

What Are Binary Quasars?

Open Questions and Research

More Research References

27 October 2015


2006 Hennawi, Joseph F Binary Quasars in the Sloan Digital Sky Survey: Evidence for Excess Clustering on Small Scale Journal/Survey

2010 Hennawi, Joseph F Binary Quasars at High Redshift. I. 24 New Quasar Pairs at z ~ 3-4

1993 Wisotzki, L.; Koehler The new double QSO HE 1104-1805: Gravitational lens with microlensing or binary quasar?

2008 Myers, Adam D Quasar Clustering at 25 h-1 kpc from a Complete Sample of Binaries Journal

1999 Kochanek, C. S. Why Quasar Pairs are Binary Quasars and Not Gravitational Lenses

2010 Shen, Yue Binary Quasars at High Redshift. II. Sub-Mpc Clustering Journal

2010 Green, Paul SDSS J1254+0846: A Binary Quasar Caught in the Act of Merging Journal

1999 Mortlock, Daniel Binary Quasars

Search Resources: http://adsabs.harvard.edu/cgi-bin/nph-basic_connect

6 November 2015

What is L* galaxy?

The Galaxy Luminosity Function

L* is the halo mass scale, the mean luminosity of central galaxies in halos at the upper end of selected mass range. [1] Empirical relations between central galaxy luminosity and the halo mass and total galaxy luminosity in a halo and the halo mass are variables for the galaxy luminosity function (LF).

With the halo mass function, this gives the observed characteristics of galaxy LF with shape for Schechter function. When all galaxies are included, regardless of the environment or Hubble type, the Schechter L* is the luminosity scale above which the central galaxy luminosity-halo mass relation flattens; L* corresponds to ~ 10^13 M. on the halo mass scale.  LC of Schechter (1976) type, Φ(L)∝Lαe^−L/L⋆, whereα is the slope of the LF at the faint end, and L⋆ is usually thought of as a characteristic luminosity scale.


1. What are Binary Quasars? (History, Importance, and Highlights of Binary Quasars. If given a binary pair, what's the state of knowledge?)

2. Open Questions: Potential paper references from recent papers? (See links)

13 November 2015

Graph and Observe: Φ(L)∝Lαe^−L/L⋆

2 different parameters: alpha and L*

spec1 spec1

*For first graph, L* should only have positive values.

Finding Redshift (using Python) Convert Z to distance by Plank13 program from astropy.cosmology, using cos law (in progress on ipython)

3. What is Radio-Loud? Referenced in luminosity site. Ex. O^2R pair?

  • Radio Jet and lobes?

Radio-Loud and Radio-Quiet describe galaxies. Radio-loud objects produce large-scale radio jets and lobes and are associated with elliptical galaxies, which have undergone recent mergers while the radio-quiets prefer spiral hosts. Host galaxies of radio-loud quasars are elliptical and those of radio-quiet quasars are spirals, consistent with the distinction at low redshift.

O^2R means O*O*R, where O refers to optical and R refers to radio

Radio Jet: material spewing from the centers of some galaxies at close to the speed of light and emitting strong radio waves Jet can be seen to emit synchrotron radiation.

Radio Lobes: Lobes only emit in the radio frequency range, and so appear red.

4 December 2015

How the universe is expanding and will affect the distance of quasars.

Expanding Confusion: common misconceptions of cosmological horizons and the superluminal expansion of the universe

Redshift Calculations: pg. 5 Quasar information: pg. 10-16

[2] http://arxiv.org/abs/astro-ph/9408005

[3] http://www.britannica.com/topic/radio-jet

[4] https://en.wikipedia.org/wiki/Radio_galaxye

Winter 2016

Goals: 1. Read up on Quasar Papers, 2. Find Quasar Separation using Ipython Notebook

28 January 2016

Readings and Questions: What is AGN, active galactic nucleus?

Quasars, a quasi-steller radio source is a class of AGN. https://en.wikipedia.org/wiki/Quasar

"For a long time it has been argued[1] that an AGN must be powered by accretion of mass onto massive black holes (106 to 1010 times the Solar mass).[2] AGN are both compact and persistently extremely luminous."

Active Galactic Nucleus

5 February 2016

*Midterms!* Gathered values to compare size of quasars to Milky Way, etc.

19 February 2016

2. Find Quasar Separation using Ipython Notebook