اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدUpdate on the BINGO 21cm intensity mapping experiment
76
0
0.0
(
0
)
تأليف
Richard Battye
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
21cm intensity mapping is a novel approach aimed at measuring the power spectrum of density fluctuations and deducing cosmological information, notably from the Baryonic Acoustic Oscillations (BAO). We give an update on the progress of BAO from Integrated Neutral Gas Observations (BINGO) which is a single dish intensity mapping project. First we explain the basic ideas behind intensity mapping concept before updating the instrument design for BINGO. We also outline the survey we plan to make and its projected science output including estimates of cosmological parameters.
قيم البحث
اقرأ أيضاً
BINGO is a concept for performing a 21cm intensity mapping survey using a single dish telescope. We briefly discuss the idea of intensity mapping and go on to define our single dish concept. This involves a sim 40 m dish with an array of sim 50 feed
horns placed sim 90 m above the dish using a pseudo-correlation detection system based on room temperature LNAs and one of the celestial poles as references. We discuss how such an array operating between 960 and 1260 MHz could be used to measure the acoustic scale to 2.4% over the redshift range 0.13<z<0.48 in around 1 year of on-source integration time by performing a 10 deg times 200 deg drift scan survey with a resolution of sim 2/3 deg.
The Baryon Mapping eXperiment (BMX) is an interferometric array designed as a pathfinder for a future post-reionization 21 cm intensity mapping survey. It consists of four 4-meter parabolic reflectors each having offset pyramidal horn feed, quad-ridg
e orthomode transducer, temperature-stabilized RF amplification and filtering, and pulsed noise injection diode. An undersampling readout scheme uses 8-bit digitizers running at 1.1 Gsamples/sec to provide access to signals from 1.1 - 1.55 GHz (third Nyquist zone), corresponding to HI emission from sources at redshift $0 < z < 0.3$. An FX correlator is implemented in GPU and generates 28 GB/day of time-ordered visibility data. About 7,000 hours of data were collected from Jan. 2019 - May 2020, and we will present results on system performance including sensitivity, beam mapping studies, observations of bright celestial targets, and system electronics upgrades. BMX is a pathfinder for the proposed PUMA intensity mapping survey in the 2030s.
[Abridged] We study the abundance and clustering properties of HI at redshifts $zleqslant5$ using TNG100, a large state-of-the-art magneto-hydrodynamic simulation of a 75 Mpc/h box size. We show that most of the HI lies within dark matter halos and q
uantify the average HI mass hosted by halos of mass M at redshift z. We find that only halos with circular velocities larger than $simeq$ 30 km/s contain HI. While the density profiles of HI exhibit a large halo-to-halo scatter, the mean profiles are universal across mass and redshift. The HI in low-mass halos is mostly located in the central galaxy, while in massive halos is concentrated in the satellites. We show that the HI and matter density probability distribution functions differ significantly. Our results point out that for small halos the HI bulk velocity goes in the same direction and has the same magnitude as the halo peculiar velocity, while in large halos differences show up. We find that halo HI velocity dispersion follows a power-law with halo mass. We find a complicated HI bias, with HI becoming non-linear already at $k=0.3$ h/Mpc at $zgtrsim3$. Our simulation reproduces the DLAs bias value from observations. We find that the clustering of HI can be accurately reproduced by perturbative methods. We identify a new secondary bias, by showing that the clustering of halos depends not only on mass but also on HI content. We compute the amplitude of the HI shot-noise and find that it is small at all redshifts. We study the clustering of HI in redshift-space, and show that linear theory can explain the ratio between the monopoles in redshift- and real-space down to small scales at high redshift. We find that the amplitude of the Fingers-of-God effect is larger for HI than for matter. We point out that accurate 21 cm maps can be created from N-body or approximate simulations rather than full hydrodynamic simulations.
The 21-cm line of neutral hydrogen (HI) opens a new avenue in our exploration of the Universes structure and evolution. It provides complementary data with different systematics, which aim to improve our current understanding of the $Lambda$CDM model
. Among several radio cosmological surveys designed to measure this line, BINGO is a single dish telescope mainly designed to detect Baryon Acoustic Oscillations (BAO) at low redshifts ($0.127 < z < 0.449$). Our goal is to assess the capabilities of the fiducial BINGO setup to constrain the cosmological parameters and analyse the effect of different instrument configurations. We will use the 21-cm angular power spectra to extract information about the HI signal and the Fisher matrix formalism to study BINGO projected constraining power. We use the Phase 1 fiducial configuration of the BINGO telescope to perform our cosmological forecasts. In addition, we investigate the impact of several instrumental setups and different cosmological models. Combining BINGO with Planck temperature and polarization data, we project a $1%$ and a $3%$ precision measurement at $68%$ CL for the Hubble constant and the dark energy (DE) equation of state (EoS), respectively, within the wCDM model. Assuming a CPL parametrization, the EoS parameters have standard deviations given by $sigma_{w_0} = 0.30$ and $sigma_{w_a} = 1.2$. We find that BINGO can also help breaking degeneracies in alternative models, which improves the cosmological constraints significantly. Moreover, we can access information about the HI density and bias, obtaining $sim 8.5%$ and $sim 6%$ precision, respectively, assuming they vary with redshift at three independent bins. The fiducial BINGO configuration will be able to extract significant information from the HI distribution and provide constraints competitive with current and future cosmological surveys. (Abridged)
We investigate the possibility of performing cosmological studies in the redshift range $2.5<z<5$ through suitable extensions of existing and upcoming radio-telescopes like CHIME, HIRAX and FAST. We use the Fisher matrix technique to forecast the bou
nds that those instruments can place on the growth rate, the BAO distance scale parameters, the sum of the neutrino masses and the number of relativistic degrees of freedom at decoupling, $N_{rm eff}$. We point out that quantities that depend on the amplitude of the 21cm power spectrum, like $fsigma_8$, are completely degenerate with $Omega_{rm HI}$ and $b_{rm HI}$, and propose several strategies to independently constraint them through cross-correlations with other probes. Assuming $5%$ priors on $Omega_{rm HI}$ and $b_{rm HI}$, $k_{rm max}=0.2~h{rm Mpc}^{-1}$ and the primary beam wedge, we find that a HIRAX extension can constrain, within bins of $Delta z=0.1$: 1) the value of $fsigma_8$ at $simeq4%$, 2) the value of $D_A$ and $H$ at $simeq1%$. In combination with data from Euclid-like galaxy surveys and CMB S4, the sum of the neutrino masses can be constrained with an error equal to $23$ meV ($1sigma$), while $N_{rm eff}$ can be constrained within 0.02 ($1sigma$). We derive similar constraints for the extensions of the other instruments. We study in detail the dependence of our results on the instrument, amplitude of the HI bias, the foreground wedge coverage, the nonlinear scale used in the analysis, uncertainties in the theoretical modeling and the priors on $b_{rm HI}$ and $Omega_{rm HI}$. We conclude that 21cm intensity mapping surveys operating in this redshift range can provide extremely competitive constraints on key cosmological parameters.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
