0307-Bicep setup

Bicep setup [ CMB ]

beam width, $\sigma$

• BICEP 2: 0.220

• Keck 2012: 0.217

• Keck 2013: 0.217

Keck Array

Keck Array is a system of BICEP2-like receivers also located at the South Pole. During the 2012 and 2013 seasons Keck Array observed the same field as BICEP2 in the same 150 GHz frequency band.

BICEP 2

BICEP2 was a specialized, low angular resolution experiment, which operated from the South Pole from 2010 to 2012, concentrating 150 GHz sensitivity comparable to Planck on a roughly 1 % patch of sky at high Galactic latitude

BK15

From 2010 to 2013, BICEP2 and Keck Array jointly recorded a total of 13 receiveryears of data in a band centered on 150 GHz. Two of the Keck receivers were switched to 95 GHz before the 2014 season, and two more were switched to 220 GHz before the 2015 season. The BK15 data set thus consists of 4/17/2 receiver-years at 95/150/220 GHz respectively.

23&33GHz of WMAP

seven polarized bands of PLANCK

BK18

In this letter [hereafter BK18] we add large amounts of new data taken by Keck Array at 220 GHz and BICEP3 at 95 GHz during the 2016, 2017 and 2018 observing seasons.

28/18/14 Keck receiver-years at 95/150/220 GHz respectively

The BICEP2 receiver observed at 150 GHz from 2010–2012 [13]. The Keck Array was essentially five copies of BICEP2 running in parallel from 2012–2019, initially at 150 GHz but switching over time to 95 and 220 GHz [14]. BICEP3 is a single similar, but scaled up, receiver which commenced science observations in the 2016 Austral winter season [15]. Whereas the BICEP2 and Keck 150 & 220 GHz receivers each contained ≈ 500 bolometric detectors BICEP3 contains ≈ 2500 detectors. The aperture size is also increased from ≈ 0.25 m to ≈ 0.5 m. The Keck receivers were mounted on a single telescope mount (movable platform), while BICEP3 occupies a separate mount previously used for BICEP2 on a nearby building.

BICEP2 and Keck:400 square degrees

BICEP3:600 square degrees