Devlin, Mark J

Email Address
ORCID
Disciplines
Research Projects
Organizational Units
Position
Introduction
Research Interests

Filters

20122
2
2
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Publication
    Atacama Cosmology Telescope: A Measurement of the Thermal Sunyaev-Zel’dovich Effect Using the Skewness of the CMB Temperature Distribution
    (2012-12-20) Wilson, Michael J; Sherwin, Blake D; Hill, J. Colin; Addison, Graeme; Battaglia, Nick; Bond, J. Richard; Das, Sudeep; Devlin, Mark J; Reese, Erik D; Swetz, Daniel S
    We present a detection of the unnormalized skewness 3(n̂)> induced by the thermal Sunyaev-Zel’dovich (tSZ) effect in filtered Atacama Cosmology Telescope (ACT) 148 GHz cosmic microwave background temperature maps. Contamination due to infrared and radio sources is minimized by template subtraction of resolved sources and by constructing a mask using outlying values in the 218 GHz (tSZ-null) ACT maps. We measure 3(n̂)>=-31±6  μK3 (Gaussian statistics assumed) or ±14  μK3 (including non-Gaussian corrections) in the filtered ACT data, a 5σ detection. We show that the skewness is a sensitive probe of σ8, and use analytic calculations and tSZ simulations to obtain cosmological constraints from this measurement. From this signal alone we infer a value of σ8=0.79-0.03+0.03 (68% C.L.) -0.06+0.06 (95% C.L.). Our results demonstrate that measurements of non-Gaussianity can be a useful method for characterizing the tSZ effect and extracting the underlying cosmological information.
  • Publication
    The Atacama Cosmology Telescope: Cross-Correlation of Cosmic Microwave Background Lensing and Quasars
    (2012-10-16) Sherwin, Blake D; Das, Sudeep; Hajian, Amir; Addison, Graeme; Bond, Richard; Crichton, Devin; Devlin, Mark J; Reese, Erik D
    We measure the cross-correlation of Atacama cosmology telescope cosmic microwave background (CMB) lensing convergence maps with quasar maps made from the Sloan Digital Sky Survey DR8 SDSS-XDQSO photometric catalog. The CMB lensing quasar cross-power spectrum is detected for the first time at a significance of 3.8σ, which directly confirms that the quasar distribution traces the mass distribution at high redshifts z>1. Our detection passes a number of null tests and systematic checks. Using this cross-power spectrum, we measure the amplitude of the linear quasar bias assuming a template for its redshift dependence, and find the amplitude to be consistent with an earlier measurement from clustering; at redshift z≈1.4, the peak of the distribution of quasars in our maps, our measurement corresponds to a bias of b=2.5±0.6. With the signal-to-noise ratio on CMB lensing measurements likely to improve by an order of magnitude over the next few years, our results demonstrate the potential of CMB lensing cross-correlations to probe astrophysics at high redshifts.