M. Zemcov

AXION DECAY AND ANISOTROPY OF NEAR-IR EXTRAGALACTIC BACKGROUND LIGHT

The extragalactic background light (EBL) is comprised of the cumulative radiation from all galaxies and active galactic nuclei over the cosmic history. In addition to point sources, EBL also contains information from diffuse sources of radiation. The angular power spectra of the near-infrared intensities could contain additional signals and a complete understanding of the nature of the IR background is still lacking in the literature. Here we explore the constraints that can be placed on particle decays, especially candidate dark matter models involving axions that trace dark matter halos of galaxies. Axions with a mass around a few eV will decay via two photons with wavelengths in the near-IR band, and will leave a signature in the IR background intensity power spectrum. Using recent power spectra measurements from the Hubble Space Telescope (HST) and Cosmic Infrared Background Experiment (CIBER), we find that the 0.6 to 1.6 micron power spectra can be explained by axions with masses around 4 eV. The total axion abundance Omega_a~0.05, and it is comparable to the baryon density of the Universe. The suggested mean axion mass and abundance are not ruled out by existing cosmological observations. Interestingly, the axion model with a mass distribution is preferred by the data, which cannot be explained by the standard quantum chromodynamics (QCD) theory and needs further discussion.

Peculiar Velocity Constraints from Five-Band SZ Effect Measurements Towards RX J1347.5-1145 with MUSIC and Bolocam from the CSO

We present Sunyaev-Zeldovich (SZ) effect measurements from wide-field images towards the galaxy cluster RX J1347.5-1145 obtained from the Caltech Submillimeter Observatory with the Multiwavelength Submillimeter Inductance Camera (MUSIC) at 147, 213, 281, and 337 GHz and with Bolocam at 140 GHz. As part of our analysis, we have used higher frequency data from Herschel-SPIRE and previously published lower frequency radio data to subtract the signal from the brightest dusty star-forming galaxies behind RX J1347.5-1145 and from the AGN in RX J1347.5-1145s BCG. Using these five-band SZ effect images, combined with X-ray spectroscopic measurements of the temperature of the intra-cluster medium (ICM) from Chandra, we constrain the ICM optical depth to be

Analysis of Dark Data of the PICNIC IR Arrays in the CIBER

tau_e = 7.33^{+0.96}_{-0.97} times 10^{-3}

A Foreground Masking Strategy for [C II] Intensity Mapping Experiments Using Galaxies Selected by Stellar Mass and Redshift

and the ICM line of sight peculiar velocity to be

LOW-RESOLUTION NEAR-INFRARED STELLAR SPECTRA OBSERVED BY THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER)

v_{pec} = -1040^{+870}_{-840}

The cosmic infrared background experiment-2 (CIBER-2) for studying the near-infrared extragalactic background light

km s

Detector modules and spectrometers for the TIME-Pilot [CII] intensity mapping experiment

^{-1}

Integration and instrument characterization of the cosmic infrared background experiment 2 (CIBER-2)

. The errors for both quantities are limited by measurement noise rather than calibration uncertainties or astrophysical contamination, and significant improvements are possible with deeper observations. Our best-fit velocity is in good agreement with one previously published SZ effect analysis and in mild tension with the other, although some or all of that tension may be because that measurement samples a much smaller cluster volume. Furthermore, our best-fit optical depth implies a gas mass slightly larger than the Chandra-derived value, implying the cluster is elongated along the line of sight.

Development of data storage system and GSE for cosmic infrared background experiment 2 (CIBER-2)

We have measured and analyzed the dark data of two PICNIC IR arrays (P574 and P560) obtained through the Cosmic Infrared Background ExpeRiment (CIBER). First, we identified three types of bad pixels: the cold, the hot, and the transient, which are figured in total as 0.06% for P574 and 0.19% for P560. Then, after the bad pixels were masked, we determined the dark noise to be 20.5 ± 0.05 e^- and 16.1 ± 0.05 e^-, and the dark current to be 0.6 ± 0.05 e^-/sec and 0.7 ± 0.05 e^-/sec for P574 and P560, respectively. Finally, we discussed glitches and readout modes for a future mission.

Spitzer Observations of the North Ecliptic Pole

Intensity mapping provides a unique means to probe the epoch of reionization (EoR), when the neutral intergalactic medium was ionized by energetic photons emitted from the first galaxies. The [C II] 158 μm fine-structure line is typically one of the brightest emission lines of star-forming galaxies and thus a promising tracer of the global EoR star formation activity. However, [C II] intensity maps at 6 ≾ z ≾ 8 are contaminated by interloping CO rotational line emission (3 ⩽ J_(upp) ⩽ 6) from lower-redshift galaxies. Here we present a strategy to remove the foreground contamination in upcoming [C II] intensity mapping experiments, guided by a model of CO emission from foreground galaxies. The model is based on empirical measurements of the mean and scatter of the total infrared luminosities of galaxies at z 10^8 M⊙ selected in the K-band from the COSMOS/UltraVISTA survey, which can be converted to CO line strengths. For a mock field of the Tomographic Ionized-carbon Mapping Experiment, we find that masking out the voxels (spectral–spatial elements) containing foreground galaxies identified using an optimized CO flux threshold results in a z-dependent criterion m^(AB)_K ≾ 22 (or M* ≳ 10^9 M⊙)) at z < 1 and makes a [C II]/CO_(tot) power ratio of ≳10 at k = 0.1 h/Mpc achievable, at the cost of a moderate ≾ 8% loss of total survey volume.