BINGO Pipeline

Poster para SAB2017

Transcript

1. Desenvolvendo a pipeline do BINGO K. Fornazier Palestra Divulgação Grupy-Dev 2017 1
2. Topics Motivation BAO - Baryon Acoustic Oscillations BINGO Pipeline 2
3. Abstract BAO (Baryon Acoustic Oscillations) are arguably one of the best probes to explore the young Universe and can contribute critically to the understanding of the Dark Energy properties. BINGO (BAO in Integrated Neutral Gas Observations) is a radio telescope designed to make the first BAO measurement in the radio waveband (~ 1 GHz). It will use a technique known as Intensity Mapping, based upon the 21 cm Hydrogen hyperfine transition. BINGO is currently in construction by a consortium including Brazil (Univ. of São Paulo and INPE), U.K (Univ. Manchester, Univ. College London), Switzerland (Zurich Politechnic Institute) and Uruguay (Univ. de la Republica and Min. de las Comunicaciones) and is planned to start operations early 2019, with a lifetime of many years. We intend to achieve very competitive results with BINGO through an innovative design, based on simplicity and careful combination of two 40 m dishes with a focal plane containing 50 horns and receivers operating in the frequency range 0.96 – 1.26 GHz, with 512 channels, achieving a total system noise temperature of ~ 50 K. This frequency range corresponds to a redshift interval z = 0.13 – 0.48, which is long after the reionization era and corresponds to an epoch where dark energy starts dominating the Universe dynamics. Dealing with the 20 GB plus of data, including 2 polarizations at each receiver output, generated daily from the instrument is a challenge in itself. The information starts from getting the time series, remove artifacts like Radio Frequency Interference (RFI), 1/f plus electronic noise, combining the data into a series of sky maps and then perform the cosmological parameter analysis. 3
4. Abstract BAO (Baryon Acoustic Oscillations) are arguably one of the best probes to explore the young Universe and can contribute critically to the understanding of the Dark Energy properties. BINGO (BAO in Integrated Neutral Gas Observations) is a radio telescope designed to make the first BAO measurement in the radio waveband (~ 1 GHz). It will use a technique known as Intensity Mapping, based upon the 21 cm Hydrogen hyperfine transition. BINGO is currently in construction by a consortium including Brazil (Univ. of São Paulo and INPE), U.K (Univ. Manchester, Univ. College London), Switzerland (Zurich Politechnic Institute) and Uruguay (Univ. de la Republica and Min. de las Comunicaciones) and is planned to start operations early 2019, with a lifetime of many years. We intend to achieve very competitive results with BINGO through an innovative design, based on simplicity and careful combination of two 40 m dishes with a focal plane containing 50 horns and receivers operating in the frequency range 0.96 – 1.26 GHz, with 512 channels, achieving a total system noise temperature of ~ 50 K. This frequency range corresponds to a redshift interval z = 0.13 – 0.48, which is long after the reionization era and corresponds to an epoch where dark energy starts dominating the Universe dynamics. Dealing with the 20 GB plus of data, including 2 polarizations at each receiver output, generated daily from the instrument is a challenge in itself. The information starts from getting the time series, remove artifacts like Radio Frequency Interference (RFI), 1/f plus electronic noise, combining the data into a series of sky maps and then perform the cosmological parameter analysis. 4
5. Motivation 5
6. Motivation 6
7. Motivation - BAO 7
8. Motivation - BAO 8
9. Motivation - BAO • Phenomenological aspects of General Relativity in the context of cosmology. • One of the main challenges is an explanation of the cosmic acceleration • It can be explained by postulating a negative pressure from a new component, known as dark energy. • In combination with other observations, such as the Cosmic Microwave Background (CMB), there is little doubt about the existence of such a component and the main focus of observational cosmology has changed to try to determine its detailed properties. 9
10. BINGO The BINGO (BAO from Integrated Neutral Gas Observations) telescope is a new instrument designed specifically for observing BAO signals, as well as other astrophysical phenomena. These observations will give us the first measurement of the BAO in the radio band and yield a fundamental contribution to the study of dark energy. Our goal is to be the first to detect BAO in the radio domain and to map the 3D distribution of hydrogen, the most abundant element of the Universe, with observations spanning at least two years. Nominal site is in Serra do Urubu, a sierra complex near Aguiar (PB), northeast Brazil https://www.google.com.br/maps/place/Aguiar+-+PB/@-7.0853851 ,-38.26752,23829m/data=!3m1!1e3!4m5!3m4!1s0x7a43b1675fbb8 f9:0x966a70b227722e65!8m2!3d-7.0866019!4d-38.2110938 10
11. BINGO 11
12. BINGO 12
13. Foregrounds spectra are expected to be smooth and can approximated by a power-law in the frequency range of interest. This property can then be used to separate the HI signal from any other signal correlated in frequency. 13 PIPELINE - Simulation of the signal and expected performance Simulation showing galactic and extragalactic foregrounds at 1GHz, the sky region that will be probed by BINGO selected in white solid lines
14. 14 PIPELINE - Simulation of the signal and expected performance Simulation showing the foreseen signal for a drift scan strip (corresponding to the probed region, grey represents non observable regions): HI emission(top), galactic and extragalactic foregrounds (bottom)
15. 15 PIPELINE - Simulation of the signal and expected performance Simulation showing, for the same region and for a drift scan, the signal from instrumental noise: thermal noise (top), 1/f noise (bottom)
16. 16 PIPELINE - Foregrounds Removal The recent trends in the foregrounds removal has been the use of blind methods such as Principal Component Analysis (PCA), which assumes nothing about the foregrounds, except that they can be described by a small number of eigenmodes, which is true if the foregrounds are spectrally smooth. PCA has the advantage of being a nonparametric method and does not require any prior knowledge on the spectra of the foregrounds
17. 17 PIPELINE Input information for this pipeline are: 1. the reprocessed 408 MHz, 2. the spectral model → which includes spatially variable spectral indices and curvature in order to be able to extrapolate to our observing frequencies, and 3. extragalactic point sources and the 21 cm signal generated by the CORA code.
18. 18 PIPELINE
19. 19 PIPELINE http://codepad.org/I6R6Iw1S
20. 20 PIPELINE - GNILC Nowadays BINGO team developed the Generalized Needlet Internal Linear Combination (GNILC), which is a non-parametric component separation technique for HI intensity mapping experiments. In general, the GNILC method can extract the emission of a multidimensional component (spatially correlated components) from the observed data, as we can see:
21. 21 PIPELINE - GNILC
22. Atuará no desenvolvimento de códigos para análise de dados em Fortran 90 e Python Requisitos: Graduação em Física, Ciência da Computação ou Engenharia Eletrônica, a partir do 3o. ano (IC); interesse em envolver-se também com a parte experimental do projeto. Iniciação Científica - Mestrado -Doutorado no Grupo de Cosmologia Experimental - INPE Interessados enviar CV Lattes para o e-mail: ca.wuensche@inpe.br 22
23. Obrigado! 23