The IRAS PSCz dipole

Rowan‐Robinson, M.; Sharpe, J.; Oliver, Seb; Keeble, Oliver; Canavezes, A.; Saunders, Will; Taylor, Andy; Valentine, Helen; Frenk, Carlos S.; Efstathiou, G.; McMahon, R. G.; White, Simon D. M.; Sutherland, William J.; Tadros, H.; Maddox, S. J.

doi:10.1046/j.1365-8711.2000.03313.x

Cited by 57 publications

(48 citation statements)

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“…Beyond 200 h −1 Mpc, no further influential structure is indicated, and the residual drift of the velocity components is easily explained by Poisson noise from the increasingly sparse outer regions. This suggests that the dipole has converged by this depth, in agreement with the findings of Rowan-Robinson et al (2000).…”

Section: Preliminary Conclusionsupporting

confidence: 88%

Local Group Velocity from the PSCz and BTP Surveys

D'Mellow

Saunders

2004

Publ. – Astron. Soc. Aust

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We present a brief overview and preliminary measure of the Local Group velocity, using the PSCz survey together with its recently completed extension into the Galactic plane, the Behind The Plane (BTP) survey. The addition of the BTP has increased the total sky coverage from 84% to 93%, drastically reducing the systematic uncertainty in the direction of the local gravitational pull caused by incomplete sky coverage. We present methods that self-consistently determine the acceleration in the presence of redshift distortions. Preliminary results suggest that the dipole converges within the survey limiting depth. There is a large, but only marginally significant, component to the dipole arising at 180-200 h −1 Mpc.Keywords: cosmology: large-scale structure -galaxies: kinematics and dynamics Behind The Plane Extension SurveyThe BTP is the low-latitude extension to the PSCz (Point Source Catalogue redshift) survey (Saunders et al. 2000a) based on the IRAS PSC, which mapped the entire sky at 12, 25, 60, and 100 µm, with nearly uniform all-sky coverage -ideal as an all-sky redshift catalogue sample base. The IRAS selection criteria were tightened for the BTP, in order to minimise contamination from Galactic sources. These criteria were S 60 > 2 S 25 and S 60 > 4 S 12 to exclude stars, and S 100 < 5 S 60 to exclude Galactic cirrus. Also excluded were areas with <2 HCONS, areas of high source density at 12, 25, and 60 µm, and areas with I 100 > 25 MJy sr −1 . The remaining unmapped sky is due to the IRAS coverage gaps (3%) and the ZOA (4%). The survey has a median depth of 8500 km s −1 with low and quantified incompleteness. The BTP consists of 1225 PSC likely or confirmed galaxies, of which 869 have positive IDs and redshifts. Completeness issues are briefly described in Saunders et al. (2000b), and will be covered in detail in the official survey release (Saunders et al., in prep.). Local Group VelocityHere we describe the problems created when using a magnitude-limited redshift sample to measure the Local Group velocity v LG . Linear gravitational instability theory states that the velocity vector can in principle, be determined by integrating the gravitational force from the density field over the entire volume of the Universe (Peebles 1980). In reality we can make an estimate of this, using a sparse sample of the density field over a sufficiently large, finite volume. By using luminous galaxies as a tracer of the underlying mass, we getHere, β = 0.6 /b, where b is the bias of the galaxy population under consideration, and ψ(r) is the selection function -the expected number density of galaxies (in the absence of clustering) meeting the survey selection criteria, as a function of position (Strauss et al. 1992). The issue being that we have a redshift-space sample, but want real-space distances to each galaxy. For many cosmological statistics, these redshift-space distortions are critical. Conversely, the Local Group velocity is only sensitive to first-order changes in the mass distribution: non-linear distor...

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Section: Preliminary Conclusionsupporting

confidence: 88%

Local Group Velocity from the PSCz and BTP Surveys

D'Mellow

Saunders

2004

Publ. – Astron. Soc. Aust

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“…To optimize our sensitivity to anisotropies in the spatial distribution of AGNs, we restricted ourselves to distances <70 Mpc, at which maximal contrasts in galaxy numbers are expected (see e.g. Rowan-Robinson et al 2000).…”

Section: Signatures Of a Large-scale Structure In The Population Of Hmentioning

confidence: 99%

“…If we take into account that the high and low AGN number density regions appear to correlate with known (from surveys of both infrared galaxies, e.g. Rowan-Robinson et al 2000, and X-ray clusters of galaxies, e.g. Kocevski & Ebeling 2006) overand under-dense regions in the local Universe, respectively, the statistical significance of the found spatial inhomogeneity will be much higher.…”

Section: Signatures Of a Large-scale Structure In The Population Of Hmentioning

confidence: 99%

“…Figure 9 demonstrates that most of the observed anisotropy in the distribution of AGNs over the sky is due to the closest (brightest) AGNs. Inclusion of sources located at progressively larger distances is expected to decrease the surface number density variations over the sky (Rowan-Robinson et al 2000). To demonstrate this, we built a map of the number density of AGNs located at D > 70 Mpc (Fig.…”

Section: Signatures Of a Large-scale Structure In The Population Of Hmentioning

confidence: 99%

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INTEGRAL/IBIS all-sky survey in hard X-rays

Krivonos

Revnivtsev

Lutovinov

et al. 2007

A&A

189

260

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We present results of an all-sky hard X-ray survey based on almost four years of observations with the IBIS telescope onboard the INTEGRAL observatory. The dead time-corrected exposure of the survey is ∼33 Ms. Approximately 12% and 80% of the sky has been covered to limiting fluxes lower than 1 and 5 mCrab, respectively. Our catalog of detected sources includes 403 objects, 316 of which exceed a 5σ detection threshold on the time-averaged map of the sky, and the rest were detected in various subsamples of exposures. Among the identified sources, 219 are Galactic (90 low-mass X-ray binaries, 76 high-mass X-ray binaries, 21 cataclysmic variables, 6 coronally active stars, and other types) and 137 are extragalactic, including 130 active galactic nuclei (AGNs) and 3 galaxy clusters. We derived number-flux functions of AGNs and Galactic sources. The log N-log S relation of non-blazar AGNs is based on 68 sources located at Galactic latitudes |b| > 5• , where the survey is characterized by high identification completeness, with fluxes higher than S lim = 1.1 × 10 −11 erg s −1 cm −2 (∼0.8 mCrab) in the 17−60 keV energy band. The cumulative AGN number-flux function can be described by a power law with a slope of 1.62 ± 0.15 and normalization of (5.7 ± 0.7) × 10 −3 sources per deg 2 at fluxes >1.43 × 10 −11 erg s −1 cm −2 (>1 mCrab). Those AGNs with fluxes higher than S lim make up ∼1% of the cosmic X-ray background at 17−60 keV. We present evidence of strong inhomogeneity in the spatial distribution of nearby ( < ∼ 70 Mpc) AGNs, which reflects the large-scale structure in the local Universe.

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“…Turnbull et al 2012). Also the issue of which structures, and on what scales, contribute to the pull on the Local Group of galaxies has still not been settled; despite some claims of the convergence of the 'clustering dipole' at distances ∼ 100 Mpc (Rowan-Robinson et al 2000;Erdogdu et al 2006), other analyses suggest influence on our motion from much larger depths (Kocevski & Ebeling 2006;Bilicki et al 2011; see also Nusser et al 2014). Finally, several other important cosmological signals -such as the integrated Sachs-Wolfe effect (ISW), CMB lensing on the large-scale structure (LSS) or baryon acoustic oscillations (BAO) -do not require full-sky coverage, but are only detectable with sufficiently wide-angle galaxy surveys probing large volumes.…”

Section: The Need For All-sky Galaxy Surveys In Three Dimensionsmentioning

confidence: 99%

Mapping the Cosmic Web with the largest all-sky surveys

Bilicki

Peacock

Jarrett³

et al. 2014

Proc. IAU

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Abstract. Our view of the low-redshift Cosmic Web has been revolutionized by galaxy redshift surveys such as 6dFGS, SDSS and 2MRS. However, the trade-off between depth and angular coverage limits a systematic three-dimensional account of the entire sky beyond the Local Volume (z < 0.05). In order to reliably map the Universe to cosmologically significant depths over the full celestial sphere, one must draw on multiwavelength datasets and state-of-the-art photometric redshift techniques. We have undertaken a dedicated program of cross-matching the largest photometric all-sky surveys -2MASS, WISE and SuperCOSMOS -to obtain accurate redshift estimates of millions of galaxies. The first outcome of these efforts -the 2MASS Photometric Redshift catalog (2MPZ, Bilicki et al. 2014a) -has been publicly released and includes almost 1 million galaxies with a mean redshift of z = 0.08. Here we summarize how this catalog was constructed and how using the WISE mid-infrared sample together with SuperCOSMOS optical data allows us to push to redshift shells of z ∼ 0.2-0.3 on unprecedented angular scales. Our catalogs, with ∼ 20 million sources in total, provide access to cosmological volumes crucial for studies of local galaxy flows (clustering dipole, bulk flow) and cross-correlations with the cosmic microwave background such as the integrated Sachs-Wolfe effect or lensing studies.

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The IRAS PSCz dipole

Cited by 57 publications

References 46 publications

Local Group Velocity from the PSCz and BTP Surveys

Local Group Velocity from the PSCz and BTP Surveys

INTEGRAL/IBIS all-sky survey in hard X-rays

Mapping the Cosmic Web with the largest all-sky surveys

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