分类： 天文学 >> 天文学 提交时间： 2023-02-19
DMRadio Collaboration
A. AlShirawi
C. Bartram
J. N. Benabou
L. Brouwer
S. Chaudhuri
H. -M. Cho
J. Corbin
W. Craddock
A. Droster
J. W. Foster
J. T. Fry
P. W. Graham
R. Henning
K. D. Irwin
F. Kadribasic
Y. Kahn
A. Keller
R. Kolevatov
S. Kuenstner
摘要： DMRadio-m$^3$ is an experiment that is designed to be sensitive to KSVZ and DFSZ QCD axion models in the 10-200 MHz (41 neV$/c^2$ - 0.83 $\mu$eV/$c^2$) range. The experiment uses a solenoidal dc magnetic field to convert an axion dark-matter signal to an ac electromagnetic response in a coaxial copper pickup. The current induced by this axion signal is measured by dc SQUIDs. In this work, we present the electromagnetic modeling of the response of the experiment to an axion signal over the full frequency range of DMRadio-m$^3$, which extends from the low-frequency, lumped-element limit to a regime where the axion Compton wavelength is only a factor of two larger than the detector size. With these results, we determine the live time and sensitivity of the experiment. The primary science goal of sensitivity to DFSZ axions across 30-200 MHz can be achieved with a $3\sigma$ live scan time of 3.7 years.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
BICEP/Keck Collaboration
P. A. R. Ade
Z. Ahmed
M. Amiri
D. Barkats
R. Basu Thakur
D. Beck
C. A. Bischoff
J. J. Bock
H. Boenish
E. Bullock
V. Buza
J. R. Cheshire
J. Connors
J. Cornelison
M. Crumrine
A. Cukierman
E. V. Denison
M. Dierickx
L. Duband
摘要： We present estimates of line-of-sight distortion fields derived from the 95 GHz and 150 GHz data taken by BICEP2, BICEP3, and Keck Array up to the 2018 observing season, leading to cosmological constraints and a study of instrumental and astrophysical systematics. Cosmological constraints are derived from three of the distortion fields concerning gravitational lensing from large-scale structure, polarization rotation from magnetic fields or an axion-like field, and the screening effect of patchy reionization. We measure an amplitude of the lensing power spectrum $A_L^{\phi\phi}=0.95 \pm 0.20$. We constrain polarization rotation, expressed as the coupling constant of a Chern-Simons electromagnetic term $g_{a\gamma} \leq 2.6 \times 10^{-2}/H_I$, where $H_I$ is the inflationary Hubble parameter, and an amplitude of primordial magnetic fields smoothed over 1 Mpc $B_{1\text{Mpc}} \leq 6.6 \;\text{nG}$ at 95 GHz. We constrain the root mean square of optical-depth fluctuations in a simple "crinkly surface" model of patchy reionization, finding $A^\tau<0.19$ ($2\sigma$) for the coherence scale of $L_c=100$. We show that all of the distortion fields of the 95 GHz and 150 GHz polarization maps are consistent with simulations including lensed-$\Lambda$CDM, dust, and noise, with no evidence for instrumental systematics. In some cases, the EB and TB quadratic estimators presented here are more sensitive than our previous map-based null tests at identifying and rejecting spurious B-modes that might arise from instrumental effects. Finally, we verify that the standard deprojection filtering in the BICEP/Keck data processing is effective at removing temperature to polarization leakage.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
BICEP/Keck Collaboration
P. A. R. Ade
Z. Ahmed
M. Amiri
D. Barkats
R. Basu Thakur
D. Beck
C. A. Bischoff
J. J. Bock
H. Boenish
E. Bullock
V. Buza
J. R. Cheshire
S. E. Clark
J. Connors
J. Cornelison
M. Crumrine
A. Cukierman
E. V. Denison
M. Dierickx
摘要： We characterize Galactic dust filaments by correlating BICEP/Keck and Planck data with polarization templates based on neutral hydrogen (HI) observations. Dust polarization is important for both our understanding of astrophysical processes in the interstellar medium (ISM) and the search for primordial gravitational waves in the cosmic microwave background (CMB). In the diffuse ISM, HI is strongly correlated with the dust and partly organized into filaments that are aligned with the local magnetic field. We analyze the deep BICEP/Keck data at 95, 150, and 220 GHz, over the low-column-density region of sky where BICEP/Keck has set the best limits on inflationary theories. We separate the HI emission into distinct velocity components and demonstrate a detection of dust polarization correlated with the local Galactic HI but not with the HI associated with Magellanic Stream I. We present a robust, multi-frequency detection of polarized dust emission correlated with the filamentary HI morphology template down to 95 GHz. We find the correlation for frequencies between 95-353 GHz to be between ~10-50% over multipoles $20<\ell<200$. We measure the spectral index of the filamentary dust component spectral energy distribution to be $\beta = 1.54 \pm 0.13$. We find no evidence for decorrelation in this region between the filaments and the rest of the dust field or from the inclusion of dust associated with the intermediate velocity HI. Finally, we explore the morphological parameter space in the HI-based filamentary model.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
J. C. Hood
A. Simpson
A. McDaniel
A. Foster
P. A. R. Ade
M. Ajello
A. J. Anderson
J. E. Austermann
J. A. Beall
A. N. Bender
B. A. Benson
F. Bianchini
L. E. Bleem
J. E. Carlstrom
C. L. Chang
P. Chaubal
H. C. Chiang
T-L. Chou
R. Citron
C. Corbett Moran
摘要： Including millimeter-wave (mm-wave) data in multi-wavelength studies of the variability of active galactic nuclei (AGN) can provide insights into AGN physics that are not easily accessible at other wavelengths. We demonstrate in this work the potential of cosmic microwave background (CMB) telescopes to provide long-term, high-cadence mm-wave AGN monitoring over large fractions of sky. We report on a pilot study using data from the SPTpol instrument on the South Pole Telescope (SPT), which was designed to observe the CMB at arcminute and larger angular scales. Between 2013 and 2016, SPTpol was used primarily to observe a single 500 deg^2 field, covering the entire field several times per day with detectors sensitive to radiation in bands centered at 95 and 150 GHz. We use SPT 150 GHz observations to create AGN light curves, and we compare these mm-wave light curves to those at other wavelengths, in particular gamma-ray and optical. In this Letter, we focus on a single source, PKS 2326-502, which has extensive, day-timescale monitoring data in gamma-ray, optical, and now mm-wave between 2013 and 2016. We find PKS 2326-502 to be in a flaring state in the first two years of this monitoring, and we present a search for evidence of correlated variability between mm-wave, optical R band, and gamma-ray observations. This pilot study is paving the way for AGN monitoring with current and upcoming CMB experiments such as SPT-3G, Simons Observatory, and CMB-S4, including multi-wavelength studies with facilities such as VRO-LSST.
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