Low noise flux estimate and data quality control monitoring in EUCLID-NISP cosmological survey
B. KubikR. BarbierPeter CalabriaA. CasteraE. ChabanatFlorence CharlieuJean-Claude ClémensAnne EaletS. FerriolW. GillardT. MaciaszekÉric PrietoF. SchirraA. SecrounBenoît SerraGérard SmadjaA. TilquinJulien Zoubian
1
Citation
8
Reference
10
Related Paper
Citation Trend
Abstract:
Euclid mission is designed to understand the dark sector of the universe. Precise redshift measurements are provided by H2RG detectors. We propose an unbiased method of fitting the flux with Poisson distributed and correlated data, which has an analytic solution and provides a reliable quality factor - fundamental features to ensure the goals of the mission. We compare our method to other techniques of signal estimation and illustrate the anomaly detection on the flight-like detectors. Although our discussion is focused on Euclid NISP instrument, much of what is discussed will be of interest to any mission using similar near-infrared sensors.The redshifts of long‐duration Gamma‐Ray Bursts (GRBs) is an important issue in the field of study, and unfortunately only 30% of Swift GRBs have their redshifts measured from optical spectroscopy. We are using the luminosity relations, wherein some measurable light curve or spectral property (e.g., spectral lag τlag or Epeak) is well correlated with the burst luminosity, along with some adopted cosmology, to measure the redshift of bursts without optical spectroscopy. By applying our method to the bursts with spectroscopic redshifts, we came up with the result that our average error in redshift is 26% and the spectroscopic redshifts falling inside our 1−σ range for 63% of the GRBs. In this paper, we applied the same method to all the long‐duration Swift bursts, and presented our redshift catalog for approximately 200 Swift bursts up to May 2007 above a low brightness threshold, each with accurately propagated error bars. Our complete catalog can be used for various demographic studies (without the complex selection effects of optical spectroscopy). From our results we see that the spectroscopic redshifts have been biased to z<2, and by using all the detected bursts, we are getting rid of the spectroscopic selection effect. Also, we found three possible high redshift GRBs, with their 1−σ lower limit much larger than z = 7. Unfortunately, as their 2−σ and 3−σ redshift lower limit drop down below z = 7, we cannot claim that they are definitely high redshift bursts.
Swift
Cite
Citations (0)
ABSTRACT We present methods to (i) graphically identify robust redshifts using emission lines in the (sub)mm regime, (ii) evaluate the capabilities of different (sub)mm practices for measuring spectroscopic redshifts, and (iii) optimize future (sub)mm observations towards increasing the fraction of robust redshifts. Using this publicly available code (https://github.com/tjlcbakx/redshift-search-graphs), we discuss scenarios where robust redshifts can be identified using both single- and multiple-line detections, as well as scenarios where the redshift remains ambiguous, even after the detection of multiple lines. Using the redshift distribution of (sub)mm samples, we quantify the efficiencies of various practices for measuring spectroscopic redshifts, including interferometers, as well as existing and future instruments specifically designed for redshift searches. Finally, we provide a method to optimize the observation strategy for future (sub)mm spectroscopic redshift searches with the Atacama Large Millimetre/submillimetre Array, where 2 mm proves indispensable for robust redshifts in the $\mathit{ z}$ = 2−4 region.
Cite
Citations (6)
In the framework of the Wave Universe concept it is shown, that the genesis of redshifts can be connected with the intra-system (endogenous) processes, which take place in astronomical systems. The existance of extremal redshift objects (quasars - QSO) with most probable z = 3.523 (3.847); 4.677; 6.947 (7.4); 10.524; 14.7; 27.79; is predicted
Cite
Citations (0)
We present a spectroscopic redshift catalogue of the SMACS J0723.3$-$7327 field ("Webb's First Deep Field") obtained from JWST/NIRISS grism spectroscopy and supplemented with JWST/NIRSpec and VLT/MUSE redshifts. The catalogue contains a total of 190 sources with secure spectroscopic redshifts, including 156 NIRISS grism redshifts, 123 of which are for sources whose redshifts were previously unknown. These new grism redshifts are secured with two or more spectroscopic features (64 sources), or with a single spectral feature whose identity is secured from the object's nine-band photometric redshift (59 sources). These are complemented with 17 NIRSpec and 48 MUSE redshifts, including six new NIRSpec redshifts identified in this work. In addition to the $z_{\rm cl}=0.39$ cluster galaxy redshifts (for which we provide $\sim$40 new NIRISS absorption-line redshifts), we also find three prominent galaxy overdensities at higher redshifts - at $z=1.1$, $z=1.4$, and $z=2.0$ - that were until now not seen in the JWST/NIRSpec and VLT/MUSE data. The paper describes the characteristics of our spectroscopic redshift sample and the methodology we have employed to obtain it. Our redshift catalogue is made available to the community at https://niriss.github.io/smacs0723.
Grism
Cite
Citations (2)
We propose an improved version of the redshift indicator developed by Atteia, which gets rid of the dependence on the burst duration and provides better estimates for high‐redshift GRBs. We present first this redshift indicator, then its calibration with HETE‐GRBs with known redshifts. We also provide an estimation of the redshift for 59 bursts, and we finally discuss the redshift distribution of HETE‐bursts and the possible other applications of this redshift indicator.
Cite
Citations (6)
Nowadays, fast radio bursts (FRBs) have been a promising probe for astronomy and cosmology. However, it is not easy to identify the redshifts of FRBs to date. Thus, no sufficient actual FRBs with identified redshifts can be used to study cosmology currently. In the past years, one has to use the simulated FRBs with "known" redshifts instead. To simulate an FRB, one should randomly assign a redshift to it from a given redshift distribution. But the actual redshift distribution of FRBs is still unknown so far. Therefore, many redshift distributions have been assumed in the literature. In the present work, we study the effect of various redshift distributions on cosmological constraints, while they are treated equally. We find that different redshift distributions lead to different cosmological constraining abilities from the simulated FRBs. This result emphasizes the importance to find the actual redshift distribution of FRBs, and reminds us of the possible bias in the FRB simulations due to the redshift distributions.
Observational cosmology
Cite
Citations (11)
After estimating and removing all ejection-related Doppler components from the redshifts of the QSOs near NGC 1068, the remaining redshift is assumed to be intrinsic. This well-studied case is the first example in which it has finally been possible to separate the intrinsic redshift component from the cosmological and other Doppler components. It is shown that this leads to intrinsic redshift components that occur at exact multiples of z = 0.062 and are defined by the relation zi = 0.062[10N - M] where N and M can have only certain discrete values. It is also shown that the intrinsic redshifts given by this relation and others obtained for different N and M-values, agree closely with the redshifts found to be preferred in analyses of quasar emission-line redshifts. It is now apparent that the peaks in the distribution of quasar emission line redshifts also occur at pure harmonics of z = 0.062. Although these peaks have previously been fitted by a log(1+z) relation, the above explanation now seems more appropriate. These results indicate that the Delta(z) = 0.062 redshift interval, long known to be present in QSO emission-line redshifts below z = 0.6, is also present in an intrinsic component of QSO redshifts up to z ~ 2. This appears to imply that the Delta(z) = 0.062 redshift interval represents a fundamental redshift spacing that arises from the very nature of the intrinsic redshifts.
QSOS
Line (geometry)
Cite
Citations (8)
The redshift distribution of all 46,400 quasars in the Sloan Digital Sky Survey (SDSS) Quasar Catalog, Third Data Release (DR3), is examined. Six peaks that fall within the redshift window below z = 4 are visible. Their positions agree with the preferred redshift values predicted by the decreasing intrinsic redshift (DIR) model. A power spectrum analysis of the full data set confirms the presence of a single significant power peak at the expected redshift period. Power peaks with the predicted period are also obtained when the upper and lower halves of the redshift distribution are examined separately. The periodicity detected is in linear z, as opposed to log(1 + z). Because the peaks in the SDSS quasar redshift distribution agree well with the preferred redshifts predicted by the intrinsic redshift relation, we conclude that this relation, and the peaks in the redshift distribution, likely both have the same origin, which may be intrinsic redshifts or a common selection effect. However, because of the way in which the intrinsic redshift relation was determined, it seems unlikely that one selection effect could have been responsible for both.
Cite
Citations (12)
ABSTRACT We present a spectroscopic redshift catalogue of the SMACS J0723.3−7327 field (‘Webb’s First Deep Field’) obtained from JWST/NIRISS grism spectroscopy and supplemented with JWST/NIRSpec and VLT/MUSE redshifts. The catalogue contains a total of 190 sources with secure spectroscopic redshifts, including 156 NIRISS grism redshifts, 123 of which are for sources whose redshifts were previously unknown. These new grism redshifts are secured with two or more spectroscopic features (64 sources), or with a single spectral feature whose identity is secured from the object’s nine-band photometric redshift (59 sources). These are complemented with 17 NIRSpec and 48 MUSE redshifts, including six new NIRSpec redshifts identified in this work. In addition to the zcl = 0.39 cluster galaxy redshifts (for which we provide ∼40 new NIRISS absorption-line redshifts), we also find three prominent galaxy overdensities at higher redshifts – at z = 1.1, z = 1.4, and z = 2.0 – that were until now not seen in the JWST/NIRSpec and VLT/MUSE data. The paper describes the characteristics of our spectroscopic redshift sample and the methodology we have employed to obtain it. Our redshift catalogue is made available to the community at https://niriss.github.io/smacs0723.
Cite
Citations (23)