Thermal SZ Effect Research Articles

MASSIVE HALOS IN MILLENNIUM GAS SIMULATIONS: MULTIVARIATE SCALING RELATIONS

The joint likelihood of observable cluster signals reflects the astrophysical evolution of the coupled baryonic and dark matter components in massive halos, and its knowledge will enhance cosmological parameter constraints in the coming era of large, multi-wavelength cluster surveys. We present a computational study of intrinsic covariance in cluster properties using halo populations derived from Millennium Gas Simulations (MGS). The MGS are re-simulations of the original 500 Mpc/h Millennium Simulation performed with gas dynamics under two different physical treatments: shock heating driven by gravity only (GO) and a second treatment with cooling and preheating (PH). We examine relationships among structural properties and observable X-ray and Sunyaev-Zel'dovich (SZ) signals for samples of thousands of halos with M_200 > 5 \times 10^{13} Msun/h and z < 2. While the X-ray scaling behavior of PH model halos at low-redshift offers a good match to local clusters, the model exhibits non-standard features testable with larger surveys, including weakly running slopes in hot gas observable--mass relations and ~10% departures from self-similar redshift evolution for 10^14 Msun/h halos at redshift z ~ 1. We find that the form of the joint likelihood of signal pairs is generally well-described by a multivariate, log-normal distribution, especially in the PH case which exhibits less halo substructure than the GO model. At fixed mass and epoch, joint deviations of signal pairs display mainly positive correlations, especially the thermal SZ effect paired with either hot gas fraction (r=0.88/0.69 for PH/GO at z=0) or X-ray temperature (r=0.62/0.83). We discuss halo mass selection by signal pairs, and find a minimum mass scatter of 4% in the \PH model by combining thermal SZ and gas fraction measurements.

Radio haloes from simulations and hadronic models – I. The Coma cluster

We use the results from a constrained, cosmological MHD simulation of the Local Universe to predict the radio halo and the gamma-ray flux from the Coma cluster and compare it to current observations. The simulated magnetic field within the Coma cluster is the result of turbulent amplification of the magnetic field during build-up of the cluster. The magnetic seed field originates from star-burst driven, galactic outflows. The synchrotron emission is calculated assuming a hadronic model. We follow four approaches with different distributions for the cosmic-ray proton (CRp) population within galaxy clusters. The radial profile the radio halo can only be reproduced with a radially increasing energy fraction within the cosmic ray proton population, reaching $>$100% of the thermal energy content at $\approx$ 1Mpc, e.g. the edge of the radio emitting region. Additionally the spectral steepening of the observed radio halo in Coma cannot be reproduced, even when accounting for the negative flux from the thermal SZ effect at high frequencies. Therefore the hadronic models are disfavored from present analysis. The emission of $\gamma$-rays expected from our simulated coma is still below the current observational limits (by a factor of $\sim$6) but would be detectable in the near future.

The Sunyaev–Zeldovich effect in superclusters of galaxies using gasdynamical simulations: the case of Corona Borealis

[Abridged] We study the thermal and kinetic Sunyaev-Zel'dovich (SZ) effect associated with superclusters of galaxies using the MareNostrum Universe SPH simulation. We consider superclusters similar to the Corona Borealis Supercluster (CrB-SC). This paper is motivated by the detection at 33GHz of a strong temperature decrement in the CMB towards the core of this supercluster. Multifrequency observations with VSA and MITO suggest the existence of a thermal SZ effect component in the spectrum of this cold spot, which would account for roughly 25% of the total observed decrement. We identify nine regions containing superclusters similar to CrB-SC, obtain the associated SZ maps and calculate the probability of finding such SZ signals arising from hot gas within the supercluster. Our results show that WHIM produces a thermal SZ effect much smaller than the observed value. Neither can summing the contribution of small clusters and galaxy groups in the region explain the amplitude of the SZ signal. When we take into account the actual posterior distribution from the observations, the probability that WHIM can cause a thermal SZ signal like the one observed is <1%, rising up to a 3.2% when the contribution of small clusters and galaxy groups is included. If the simulations provide a suitable description of the gas physics, then we conclude that the thermal SZ component of the CrB spot most probably arises from an unknown galaxy cluster along the line of sight. The simulations also show that the kinetic SZ signal associated with the supercluster cannot provide an explanation for the remaining 75% of the observed cold spot in CrB.

Effect of a chameleon scalar field on the cosmic microwave background

We show that a direct coupling between a chameleonlike scalar field and photons can give rise to a modified Sunyaev-Zel'dovich (SZ) effect in the cosmic microwave background (CMB). The coupling induces a mixing between chameleon particles and the CMB photons when they pass through the magnetic field of a galaxy cluster. Both the intensity and the polarization of the radiation are modified. The degree of modification depends strongly on the properties of the galaxy cluster such as magnetic field strength and electron number density. Existing SZ measurements of the Coma cluster enable us to place constraints on the photon-chameleon coupling. The constrained conversion probability in the cluster is ${\mathcal{P}}_{\mathrm{Coma}}(204\text{ }\text{ }\mathrm{GHz})&lt;6.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ at 95% confidence, corresponding to an upper bound on the coupling strength of ${g}_{\mathrm{eff}}^{(\mathrm{cell})}&lt;2.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$ or ${g}_{\mathrm{eff}}^{(\mathrm{Kolmo})}&lt;(7.2--32.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$, depending on the model that is assumed for the cluster magnetic field structure. We predict the radial profile of the chameleonic CMB intensity decrement. We find that the chameleon effect extends farther toward the edges of the cluster than the thermal SZ effect. Thus we might see a discrepancy between the x-ray emission data and the observed SZ intensity decrement. We further predict the expected change to the CMB polarization arising from the existence of a chameleonlike scalar field. These predictions could be verified or constrained by future CMB experiments.

A MEASUREMENT OF LARGE-SCALE PECULIAR VELOCITIES OF CLUSTERS OF GALAXIES: TECHNICAL DETAILS

This paper presents detailed analysis of large-scale peculiar motions derived from a sample of ~ 700 X-ray clusters and cosmic microwave background (CMB) data obtained with WMAP. We use the kinematic Sunyaev-Zeldovich (KSZ) effect combining it into a cumulative statistic which preserves the bulk motion component with the noise integrated down. Such statistic is the dipole of CMB temperature fluctuations evaluated over the pixels of the cluster catalog (Kashlinsky & Atrio-Barandela 2000). To remove the cosmological CMB fluctuations the maps are Wiener-filtered in each of the eight WMAP channels (Q, V, W) which have negligible foreground component. Our findings are as follows: The thermal SZ (TSZ) component of the clusters is described well by the Navarro-Frenk-White profile expected if the hot gas traces the dark matter in the cluster potential wells. Such gas has X-ray temperature decreasing rapidly towards the cluster outskirts, which we demonstrate results in the decrease of the TSZ component as the aperture is increased to encompass the cluster outskirts. We then detect a statistically significant dipole in the CMB pixels at cluster positions. Arising exclusively at the cluster pixels this dipole cannot originate from the foreground or instrument noise emissions and must be produced by the CMB photons which interacted with the hot intracluster gas via the SZ effect. The dipole remains as the monopole component, due to the TSZ effect, vanishes within the small statistical noise out to the maximal aperture where we still detect the TSZ component. We demonstrate with simulations that the mask and cross-talk effects are small for our catalog and contribute negligibly to the measurements. The measured dipole thus arises from the KSZ effect produced by the coherent large scale bulk flow motion.

Measuring AGN Feedback with the Sunyaev‐Zel’dovich Effect

One of the most important and poorly-understood issues in structure formation is the role of outflows driven by active galactic nuclei (AGN). Using large-scale cosmological simulations, we compute the impact of such outflows on the small-scale distribution of the cosmic microwave background (CMB). Like gravitationally-heated structures, AGN outflows induce CMB distortions both through thermal motions and peculiar velocities, by processes known as the thermal and kinetic Sunyaev-Zel'dovich (SZ) effects, respectively. For AGN outflows the thermal SZ effect is dominant, doubling the angular power spectrum on arcminute scales. But the most distinct imprint of AGN feedback is a substantial increase in the thermal SZ distortions around elliptical galaxies, post-starburst ellipticals, and quasars, which is linearly proportional to the outflow energy. While point source subtraction is difficult for quasars, we show that by appropriately stacking microwave measurements around early-type galaxies, the new generation of small-scale microwave telescopes will be able to directly measure AGN feedback at the level important for current theoretical models.

Statistical properties of SZ and X-ray cluster detections

Aims. We calibrate the number density, completeness, reliability and the lower mass limit of galaxy-cluster detections through their thermal SZ signal, and compare them to X-ray cluster detections. Methods. We simulate maps of the thermal SZ effect and the X-ray emission from light cones constructed in a large, hydrodynamical, cosmological simulation volume, including realistic noise contributions. The maps are convolved with linear, optimised, single- and multi-band filters to identify local peaks and their signal-to-noise ratios. The resulting peak catalogues are then compared to the halo population in the simulation volume to identify true and spurious detections. Results. Multi-band filtering improves the statistics of SZ cluster detections considerably compared to single-band filtering. Observations with the characteristics of ACT detect clusters with masses M>6-9e13 M_o/h, quite independent of redshift, reach 50% completeness at ~1e14 M_o/h and 100% completeness at ~2e14 M_o/h. Samples are contaminated by only a few per cent spurious detections. This is broadly comparable to X-ray cluster detections with XMM-Newton with 100 ks exposure time in the soft band, except that the mass limit for X-ray detections increases much more steeply with redshift than for SZ detections. A comparison of true and filtered signals in the SZ and X-ray maps confirms that the filters introduce at most a negligible bias.

Kinematic Sunyaev-Zel'dovich Cosmic Microwave Background Temperature Anisotropies Generated by Gas in Cosmic Structures

If the gas in filaments and halos shares the same velocity field as the luminous matter, it will generate measurable temperature anisotropies due to the kinematic Sunyaev-Zel'dovich effect. We compute the distribution function of the KSZ signal produced by a typical filament and show it is highly non-Gaussian. The combined contribution of the thermal and kinematic SZ effects of a filament of size -->L 5 Mpc and electron density -->ne 103 m?3 could explain the cold spot of ? ~ ?200 ?K on scales of -->30' found in the Corona Borealis supercluster by the VSA experiment. Planck, with its large resolution and frequency coverage, could provide the first evidence of the existence of filaments in this region. The KSZ contribution of the network of filaments and halo structures to the radiation power spectrum peaks around -->l ~ 400, a scale very different from that of clusters of galaxies, with a maximum amplitude -->l(l + 1) Cl/2? ~ 10?25 (?K)2, depending on model parameters, i.e., -->?8 and the Jeans length. About 80% of the signal comes from filaments with redshift -->z ? 0.1. Adding this component to the intrinsic cosmic microwave background temperature anisotropies of the concordance model improves the fit to WMAP 3 yr data by -->? ?2 1. The improvement is not statistically significant but a more systematic study could demonstrate that gas could significantly contribute to the anisotropies measured by WMAP.

Direct probes of dark matter in the cluster 1ES0657-556 through microwave observations

The cluster 1ES0657-556 is an ideal astrophysical laboratory to study the distribution and the nature of Dark Matter because this last component is spatially separated from the intracluster gas. We show that microwave observations can provide crucial probes of Dark Matter in this system. We calculate the expected SZ effect from Dark Matter annihilation in the main mass concentrations of the cluster 1ES0657-556, and we estimate the sources of contamination, confusion and bias to asses its significance. We find that SZ observations at a frequency of 223 GHz can resolve both spatially and spectrally the SZ_DM signal and isolate it from the other SZ signals, and mainly from the thermal SZ effect which is null at frequencies 220-223 GHz for the case of 1ES0657-556. We conclude that SZ observations with sub-arcmin resolution and micro-K sensitivity of 1ES0657-556 are crucial, and maybe unique, to find direct astrophysical probes of the existence and of the nature of Dark Matter, or to set strong experimental limits.

AGN Heating, Thermal Conduction, and the Sunyaev‐Zel'dovich Effect in Galaxy Groups and Clusters

We investigate in detail the role of active galactic nuclei (AGNs) in the physical state of the gas in galaxy groups and clusters, and the implications for anisotropy in the cosmic microwave background (CMB) from the Sunyaev-Zel'dovich (SZ) effect. We have recently shown that AGNs can significantly change the entropy of the intracluster medium (ICM) and explain the observations of excess entropy in groups and clusters. AGNs are assumed to deposit energy via buoyant bubbles that expand as they rise in the cluster atmosphere and do P dV work on the ICM. Here we include the effect of thermal conduction and find that the resulting profiles of temperature and entropy are consistent with observations. Unlike previously proposed models, our model predicts that isentropic cores are not an inevitable consequence of preheating. The model also reproduces the observational trend for the density profiles to flatten in lower mass systems. We deduce the energy (Eagn) required to explain the entropy observations as a function of mass of groups and clusters (Mcluster) and show that Eagn ∝ M with α ~ 1.5. We demonstrate that the entropy measurements, in conjunction with our model, can be translated into constraints on the cluster-black hole mass relation. The inferred relation is nonlinear and has the form Mbh ∝ M. This scaling is an analog and extension of a similar relation between the black hole mass and the galactic halo mass that holds on smaller scales. In addition, we study the implications of these results for the thermal SZ effect. We show that the central decrement of the CMB temperature is reduced due to the enhanced entropy of the ICM and that the decrement predicted from the plausible range of energy input from the AGN is consistent with available data on the SZ decrement. We also estimate the Poisson contribution to the angular power spectrum of the CMB from the SZ effect due to AGN heating. We show that AGN heating, combined with the observational constraints on entropy, leads to suppression of higher multipole moments in the power spectrum, and we find that this effect is stronger than previously thought. The suppression in the power spectrum in our model is due to depletion of gas from the central regions that is more efficient in low-mass clusters and groups than in massive clusters.

Sunyaev-Zel'dovich cluster survey simulations forPlanck

We examine the ability of the future Planck mission to provide a catalogue of galaxy clusters observed via their Sunyaev–Zel'dovich (SZ) distortion in the cosmic microwave background (CMB). For this purpose we produce full-sky SZ maps based on N-body simulations and scaling relations between cluster properties for several cosmological models. We extrapolate the N-body simulations by a mass function to high redshifts in order to obtain a realistic SZ background. The simulated Planck observations include, besides the thermal and kinematic SZ effects, contributions from the primordial CMB, extragalactic point sources as well as Galactic dust, free–free and synchrotron emission. A harmonic-space maximum-entropy method is used to separate the SZ signal from contaminating components in combination with a cluster detection algorithm based on thresholding and flux integration to identify clusters and to obtain their fluxes. We estimate a survey sensitivity limit (depending on the quality of the recovered cluster flux) and provide cluster survey completeness and purity estimates. We find that, given our modelling and detection algorithm, Planck will reliably detect at least several thousands of clusters over the full sky. The exact number depends on the particular cosmological model (up to 10000 cluster detections in a concordance ΛCDM model with σ8= 0.9). We show that the Galaxy does not significantly affect the cluster detection. Furthermore, the dependence of the thermal SZ power spectrum on the matter variance on scales of 8 h−1 Mpc and the quality of its reconstruction by the employed method are investigated. Our simulations suggest that the Planck cluster sample will not only be useful as a basis for follow-up observations, but also will have the ability to provide constraints on cosmological parameters.

Cross-terms and weak frequency-dependent signals in the cosmic microwave background sky

In this paper, we study the amplification of weak frequency dependent signals in the CMB sky due to their cross correlation to intrinsic anisotropies. In particular, we center our attention on mechanisms generating some weak signal, of peculiar spectral behaviour, such as resonant scattering in ionic, atomic or molecular lines, thermal SZ effect or extragalactic foreground emissions, whose typical amplitude (denoted by ǫ) is sufficiently smaller than the intrinsic CMB fluctuations. We find that all these effects involve either the autocorrelation of anisotropies generated during recombination (zrec) or the cross-correlation of those anisotropies with fluctuations arising at redshift zi. The former case accounts for the slight blurring of original anisotropies generated in the last scattering surface, and shows up in the small angular scale (high multipole) range. The latter term describes, instead, the generation of new anisotropies, and is non-zero only if fluctuations generated at redshifts zrec, zi are correlated. The degree of this correlation can be computed under the assumption that density fluctuations were generated as standard inflationary models dictate and that they evolved in time according to linear theory. In case that the weak signal is frequency dependent, (i.e., the spectral dependence of the secondary anisotropies is distinct from that of the CMB), we show that, by substracting power spectra at different frequencies, it is possible to avoid the limit associated to Cosmic Variance and unveil weaker terms linear in ǫ. We find that the correlation term shows a different spectral dependence than the squared (/ ǫ 2 ) term considered usually, making its extraction particularly straightforward for the thermal SZ effect. Furthermore, we find that in most cases the correlation terms are particularly relevant at low multipoles due to the ISW effect and must be taken into account when characterising the power spectrum associated to weak signals in the large angular scales.

The SZ effect from cluster cavities

In this Letter we derive the SZ effect (SZE) observable in the direction of the giant X-ray cavities found in the atmospheres of galaxy clusters. We explore specifically the case of the cluster MS0735.6+7421. The SZE produced in the cavities embedded in the cluster thermal atmosphere is of non-thermal nature: it dominates the overall cluster SZE at the frequency x_{0,th} - at which the thermal SZE from the cluster vanishes - and appears, at mm and sub-mm frequencies, as a negative SZE located only in the regions of the intracluster space occupied by the cavities. We show that SZ observations, combined with X-ray and radio data, are able to shed light on the morphology, on the physical structure, on the dynamics and the origin of these recently discovered non-thermal features of galaxy clusters. These studies will be also relevant to determine the impact of specific events of the nature of cavities on the use of SZ and X-ray clusters as probes for cosmology and for the large scale structure of the universe.

Clusters of galaxies in the microwave band: Influence of the motion of the Solar System

We consider the changes of the SZ cluster brightness, flux and number counts induced by the motion of the Solar System with respect to the frame defined by the cosmic microwave background (CMB). These changes are connected to the Doppler effect and aberration and exhibit a strong spectral and spatial dependence. The correction to the SZ cluster brightness and flux has an amplitude and spectral dependence, which is similar to the first order cluster peculiar velocity correction to the thermal SZ effect and hence may lead to a ∼10% correction to the kinetic SZ effect. Due to the change in the received cluster CMB flux, the motion of the Solar System induces a dipolar asymmetry in the observed number of clusters above a given flux level. Similar effects were discussed for γ-ray bursts and radio galaxies, but here, due to the very peculiar frequency-dependence of the thermal SZ effect, the number of observed clusters in one direction of the sky can be both decreased or increased depending on the frequency band.

POSSIBLE MERGER SIGNATURE IN SZ MAPS

We propose an analytical model to estimate the influence of a merger on the thermal SZ effect. Following observations we distinguish between subsonic and transonic mergers. Using analytical velocity fields and the Bernoulli equation we calculate the excess pressure around a moving subcluster for an incompressible subsonic gas. Positive excess around the stagnation point and negative excess on the side of the subcluster lead to characteristic signatures in the SZ map, of the order of compared to the unperturbed signal. For a transonic merger we calculate the change in the thermal spectral SZ function, resulting from bow shock accelerated electrons. The merger shock compression factor determines the power law tail of the new non-thermal electron population and is directly related to a shift in the crossover frequency. This shift is typically a few percent towards higher frequencies.

Measuring Cluster Peculiar Velocities and Temperatures at Centimeter and Millimeter Wavelengths

I present a detailed investigation of issues related to the measurement of peculiar velocities and temperatures using Sunyaev-Zel'dovich (SZ) effects and estimate the accuracy to which peculiar velocities and gas temperatures of distant galaxy clusters could be measured. With μK sensitivity on arcminute scales at several frequencies it will be possible to measure peculiar velocities to an accuracy of ~130 km s-1 and gas temperatures to better than 1 keV. The limiting factor for the accuracy of vpec is the presence of bulk motions within the galaxy cluster, even for apparently relaxed clusters. The accuracy of the temperature is mainly limited by noise. These results are independent of redshift, provided the clusters of interest are distant (z 0.15). Using only three frequencies, the optimal strategy is to place one observing frequency in the Rayleigh-Jeans region (ν < 40 GHz), one near 150 GHz, and the third at 300 GHz or higher. Measurements at the null of the thermal SZ effect are of marginal utility, other than as a foreground/background monitor.

Discriminating between unresolved point sources and 'negative' Sunyaev-Zel'dovich clusters in cosmic microwave background maps

Clusters of galaxies produce negative features at wavelengths λ > 1.25 mm in CMB maps, by means of the thermal SZ effect, while point radio sources produce positive peaks. This fact implies that a distribution of unresolved SZ clusters could be detected using the negative asymmetry introduced in the odd-moments of the brightness map (skewness and higher), or in the probability distribution function (PDF) for the fluctuations, once the map has been filtered in order to remove the contribution from primordial CMB fluctuations from large scales. This property provides a consistency check to the recent detections from CBI and BIMA experiments of an excess of power at small angular scales, in order to confirm that they are produced by a distribution of unresolved SZ clusters. However it will require at least 1.5 - 2 times more observing time than detection of corresponding power signal. This approach could also be used with the data of the planned SZ experiments (e.g. ACT, AMI, AMIBA, APEX, 8 m South Pole telescope).

The non-thermal Sunyaev–Zel'dovich effect in clusters of galaxies

In this paper we provide a general derivation of the non-thermal (as well as of the thermal) SZ effect in galaxy clusters which is exact in the Thomson limit to any approximation order in the optical depth. Such a general derivation is obtained using the full relativistic formalism and overcoming the limitations of the Kompaneets and of the single scattering approximations. To have a consistent description of the SZ effect in clusters containing non-thermal phenomena, we also evaluate in a consistent way - for the first time - the total SZ effect produced by a combination of thermal and non-thermal electron populations residing in the same environment, like is the case in radio-halo clusters. We discuss both the spectral and the spatial features of the total SZ effect and we provide specific predictions for a well studied radio-halo cluster like A2163. We also discuss the overall SZ effect produced by a combination of different thermal populations residing in the cluster atmosphere. In this context, we discuss how the combined observations of the thermal and non-thermal SZ effect provide constraints on the spectrum of the relativistic electron population and, in turn, on the presence and on the origin of non-thermal phenomena (radio-halo, hard X-ray, EUV excesses) occurring in galaxy clusters.

The Sunyaev‐Zeldovich Effect: Simulations and Observations

The Sunyaev-Zeldovich effect (SZ effect) is a complete probe of ionized baryons, the majority of which are likely hiding in the intergalactic medium. We ran a 5123 Λ cold dark matter simulation using a moving mesh hydro code to compute the statistics of the thermal and kinetic SZ effect such as the power spectra and measures of non-Gaussianity. The thermal SZ power spectrum has a very broad peak at multipole l ~ 2000-104 with temperature fluctuations ΔT ~ 15 μK. The power spectrum is consistent with available observations and suggests a high σ8 ≃ 1.0 and a possible role for nongravitational heating. The non-Gaussianity is significant and increases the cosmic variance of the power spectrum by a factor of ~5 for l < 6000. We explore optimal drift-scan survey strategies for the Array for Microwave Background Anisotropy and their dependence on cosmology. For SZ power spectrum estimation, we find that the optimal sky coverage for 1000 hr of integration time is several hundred square degrees. One achieves an accuracy better than 40% in the SZ measurement of the power spectrum and an accuracy better than 20% in the cross-correlation with Sloan galaxies for 2000 < l < 5000. For cluster searches, the optimal scan rate is around 280 hr deg-2 with a cluster detection rate of one every 7 hr, allowing for a false positive rate of 20% and better than 30% accuracy in the cluster SZ distribution function measurement.

Erratum: Sunyaev-Zel'dovich distortion from early galactic winds

We consider the distortion in the cosmic microwave background (CMB) due to galactic winds at high redshift. Winds outflowing from galaxies have been hypothesized to be possible sources of metals in the intergalactic medium, which is known to have been enriched to $10^{-2.5}$ Z$_{\odot}$ at $z \sim 3$. We model these winds as functions of mass of the parent galaxy and redshift, assuming they activate at a common initial redshift, $z_{in}$, and calculate the mean $y$ distortion and the angular power spectrum of the distortion in the CMB. We find that the thermal Sunyaev-Zel'dovich (SZ) effect due to the winds to be consistent with previous estimates. The distortion due to the kinetic SZ (kSZ) effect is, however, found to be more important than the thermal SZ (tSZ) effect. We find that the distortion due to galactic winds is an important contribution to the power spectrum of distortion at very small angular scales $(l \sim 10^4)$. We also find that the power spectrum due to clustering dominates the Poisson power spectrum for $l \le 4\hbox{--}5 \times 10^5$. We show explicitly how the combined power spectrum from wind dominates over that of clusters at 217 GHz, relevant for PLANCK. We also show how these constraints change when the efficiency of the winds is varied.