Browsing by Author "Becker, Daniel T."

Now showing 1 - 7 of 7
  • No Thumbnail Available
    Item
    Atacama Cosmology Telescope: Combined kinematic and thermal Sunyaev-Zel'dovich measurements from BOSS CMASS and LOWZ halos
    (2021) Schaan, Emmanuel; Ferraro, Simone; Amodeo, Stefania; Battaglia, Nicholas; Aiola, Simone; Austermann, Jason E.; Beall, James A.; Bean, Rachel; Becker, Daniel T.; Bond, Richard J.; Calabrese, Erminia; Calafut, Victoria; Choi, Steve K.; Denison, Edward, V; Devlin, Mark J.; Duff, Shannon M.; Duivenvoorden, Adriaan J.; Dunkley, Jo; Dunner, Rolando; Gallardo, Patricio A.; Guan, Yilun; Han, Dongwon; Hill, J. Colin; Hilton, Gene C.; Hilton, Matt; Hlozek, Renee; Hubmayr, Johannes; Huffenberger, Kevin M.; Hughes, John P.; Koopman, Brian J.; MacInnis, Amanda; McMahon, Jeff; Madhavacheril, Mathew S.; Moodley, Kavilan; Mroczkowski, Tony; Naess, Sigurd; Nati, Federico; Newburgh, Laura B.; Niemack, Michael D.; Page, Lyman A.; Partridge, Bruce; Salatino, Maria; Sehgal, Neelima; Schillaci, Alessandro; Sifon, Cristobal; Smith, Kendrick M.; Spergel, David N.; Staggs, Suzanne; Storer, Emilie R.; Trac, Hy; Ullom, Joel N.; Van Lanen, Jeff; Vale, Leila R.; van Engelen, Alexander; Magana, Mariana Vargas; Vavagiakis, Eve M.; Wollack, Edward J.; Xu, Zhilei
    The scattering of cosmic microwave background (CMB) photons off the free-electron gas in galaxies and clusters leaves detectable imprints on high resolution CMB maps: the thermal and kinematic Sunyaev-Zel'dovich effects (tSZ and kSZ respectively). We use combined microwave maps from the Atacama Cosmology Telescope DR5 and Planck in combination with the CMASS (mean redshift (z) = 0.55 and host halo mass (M-vir) = 3 x 10(13) M-circle dot) and LOWZ ((z) = 0.31, (M-vir) = 5 x 10(13) M-circle dot) galaxy catalogs from the Baryon Oscillation Spectroscopic Survey (BOSS DR10 and DR12), to study the gas associated with these galaxy groups. Using individual reconstructed velocities, we perform a stacking analysis and reject the no-kSZ hypothesis at 6.5 sigma, the highest significance to date. This directly translates into a measurement of the electron number density profile, and thus of the gas density profile. Despite the limited signal to noise, the measurement shows at high significance that the gas density profile is more extended than the dark matter density profile, for any reasonable baryon abundance (formally >90 sigma for the cosmic baryon abundance). We simultaneously measure the tSZ signal, i.e., the electron thermal pressure profile of the same CMASS objects, and reject the no-tSZ hypothesis at 10 sigma. We combine tSZ and kSZ measurements to estimate the electron temperature to 20% precision in several aperture bins, and find it comparable to the virial temperature. In a companion paper, we analyze these measurements to constrain the gas thermodynamics and the properties of feedback inside galaxy groups. We present the corresponding LOWZ measurements in this paper, ruling out a null kSZ (tSZ) signal at 2.9 (13.9)sigma, and leave their interpretation to future work. This paper and the companion paper demonstrate that current CMB experiments can detect and resolve gas profiles in low mass halos and at high redshifts, which are the most sensitive to feedback in galaxy formation and the most difficult to measure any other way. They will be a crucial input to cosmological hydrodynamical simulations, thus improving our understanding of galaxy formation. These precise gas profiles arc already sufficient to reduce the main limiting theoretical systematic in galaxy-galaxy lensing: baryonic uncertainties. Future such measurements will thus unleash the statistical power of weak lensing from the Rubin, Euclid and Roman observatories. Our stacking software ThumbStackis publicly available and directly applicable to future Simons Observatory and CMB-S4 data.
  • Thumbnail Image
    Item
    Atacama Cosmology Telescope: Constraints on cosmic birefringence
    (AMER PHYSICAL SOC, 2020) Namikawa, Toshiya; Guan, Yilun; Darwish, Omar; Sherwin, Blake D.; Aiola, Simone; Battaglia, Nicholas; Beall, James A.; Becker, Daniel T.; Bond, J. Richard; Calabrese, Erminia; Chesmore, Grace E.; Choi, Steve K.; Devlin, Mark J.; Dunkley, Joanna; Dunner, Rolando; Fox, Anna E.; Gallardo, Patricio A.; Gluscevic, Vera; Han, Dongwon; Hasselfield, Matthew; Hilton, Gene C.; Hincks, Adam D.; Hlozek, Renee; Hubmayr, Johannes; Huffenberger, Kevin; Hughes, John P.; Koopman, Brian J.; Kosowsky, Arthur; Louis, Thibaut; Lungu, Marius; MacInnis, Amanda; Madhavacheril, Mathew S.; Mallaby Kay, Maya; Maurin, Loic; McMahon, Jeffrey; Moodley, Kavilan; Naess, Sigurd; Nati, Federico; Newburgh, Laura B.; Nibarger, John P.; Niemack, Michael D.; Page, Lyman A.; Qu, Frank J.; Robertson, Naomi; Schillaci, Alessandro; Sehgal, Neelima; Sifon, Cristobal; Simon, Sara M.; Spergel, David N.; Staggs, Suzanne T.; Storer, Emilie R.; van Engelen, Alexander; van Lanen, Jeff; Wollack, Edward J.
    We present new constraints on anisotropic birefringence of the cosmic microwave background polarization using two seasons of data from the Atacama Cosmology Telescope covering 456 square degrees of sky. The birefringence power spectrum, measured using a curved-sky quadratic estimator, is consistent with zero. Our results provide the tightest current constraint on birefringence over a range of angular scales between 5 arc minutes and 9 degrees. We improve previous upper limits on the amplitude of a scale-invariant birefringence power spectrum by a factor of between 2 and 3. Assuming a nearly massless axion field during inflation, our result is equivalent to a 2 sigma upper limit on the Chern-Simons coupling constant between axions and photons of g(alpha gamma) < 4.0 x 10(-2)/H-I, where H-I is the inflationary Hubble scale.
  • No Thumbnail Available
    Item
    Atacama Cosmology Telescope: Modeling the gas thermodynamics in BOSS CMASS galaxies from kinematic and thermal Sunyaev-Zel'dovich measurements
    (2021) Amodeo, Stefania; Battaglia, Nicholas; Schaan, Emmanuel; Ferraro, Simone; Moser, Emily; Aiola, Simone; Austermann, Jason E.; Beall, James A.; Bean, Rachel; Becker, Daniel T.; Bond, Richard J.; Calabrese, Erminia; Calafut, Victoria; Choi, Steve K.; Denison, Edward, V; Devlin, Mark; Duff, Shannon M.; Duivenvoorden, Adriaan J.; Dunkley, Jo; Dunner, Rolando; Gallardo, Patricio A.; Hall, Kirsten R.; Han, Dongwon; Hill, J. Colin; Hilton, Gene C.; Hilton, Matt; Hlozek, Renee; Hubmayr, Johannes; Huffenberger, Kevin M.; Hughes, John P.; Koopman, Brian J.; MacInnis, Amanda; McMahon, Jeff; Madhavacheril, Mathew S.; Moodley, Kavilan; Mroczkowski, Tony; Naess, Sigurd; Nati, Federico; Newburgh, Laura B.; Niemack, Michael D.; Page, Lyman A.; Partridge, Bruce; Schillaci, Alessandro; Sehgal, Neelima; Sifon, Cristobal; Spergel, David N.; Staggs, Suzanne; Storer, Emilie R.; Ullom, Joel N.; Vale, Leila R.; van Engelen, Alexander; Van Lanen, Jeff; Vavagiakis, Eve M.; Wollack, Edward J.; Xu, Zhilei
    The thermal and kinematic Sunyaev-Zel'dovich effects (tSZ, kSZ) probe the thermodynamic properties of the circumgalactic and intracluster medium (CGM and ICM) of galaxies, groups, and clusters, since they are proportional, respectively, to the integrated electron pressure and momentum along the line of sight. We present constraints on the gas thermodynamics of CMASS (constant stellar mass) galaxies in the Baryon Oscillation Spectroscopic Survey using new measurements of the kSZ and tSZ signals obtained in a companion paper [Schaan et al.]. Combining kSZ and tSZ measurements, we measure within our model the amplitude of energy injection epsilon M.c(2) , where M-* is the stellar mass, to be epsilon = (40 +/- 9) x 10(-6) , and the amplitude of the nonthermal pressure profile to be alpha(Nth) < 0.2(2 sigma), indicating that less than 20% of the total pressure within the virial radius is due to a nonthermal component. We estimate the effects of including baryons in the modeling of weak-lensing galaxy cross-correlation measurements using the best-fit density profile from the kSZ measurement. Our estimate reduces the difference between the original theoretical model and the weak-lensing galaxy cross-correlation measurements in [A. Leauthaud et al., Mon. Not. R. Astron. Soc. 467, 3024 (2017)] by half (50% at most), but does not fully reconcile it. Comparing the kSZ and tSZ measurements to cosmological simulations, we find that they underpredict the CGM pressure and to a lesser extent the CGM density at larger radii with probabilities to exceed ranging from 0.00 to 0.03 and 0.12 to 0.14, for tSZ and kSZ, respectively. This suggests that the energy injected via feedback models in the simulations that we compared against does not sufficiently heat the gas at these radii. We do not find significant disagreement at smaller radii. These measurements provide novel tests of current and future simulations. This work demonstrates the power of joint, high signal-to-noise kSZ and tSZ observations, upon which future cross-correlation studies will improve.
  • No Thumbnail Available
    Item
    The Atacama Cosmology Telescope: a CMB lensing mass map over 2100 square degrees of sky and its cross-correlation with BOSS-CMASS galaxies
    (2021) Darwish, Omar; Madhavacheril, Mathew S.; Sherwin, Blake D.; Aiola, Simone; Battaglia, Nicholas; Beall, James A.; Becker, Daniel T.; Bond, J. Richard; Calabrese, Erminia; Choi, Steve K.; Devlin, Mark J.; Dunkley, Jo; Dunner, Rolando; Ferraro, Simone; Fox, Anna E.; Gallardo, Patricio A.; Guan, Yilun; Halpern, Mark; Han, Dongwon; Hasselfield, Matthew; Hill, J. Colin; Hilton, Gene C.; Hilton, Matt; Hincks, Adam D.; Ho, Shuay-Pwu Patty; Hubmayr, J.; Hughes, John P.; Koopman, Brian J.; Kosowsky, Arthur; Van Lanen, J.; Louis, Thibaut; Lungu, Marius; MacInnis, Amanda; Maurin, Loic; McMahon, Jeffrey; Moodley, Kavilan; Naess, Sigurd; Namikawa, Toshiya; Nati, Federico; Newburgh, Laura; Nibarger, John P.; Niemack, Michael D.; Page, Lyman A.; Partridge, Bruce; Qu, Frank J.; Robertson, Naomi; Schillaci, Alessandro; Schmitt, Benjamin; Sehgal, Neelima; Sifon, Cristobal; Spergel, David N.; Staggs, Suzanne; Storer, Emilie; van Engelen, Alexander; Wollack, Edward J.
    We construct cosmic microwave background lensing mass maps using data from the 2014 and 2015 seasons of observations with the Atacama Cosmology Telescope (ACT). These maps cover 2100 square degrees of sky and overlap with a wide variety of optical surveys. The maps are signal dominated on large scales and have fidelity such that their correlation with the cosmic infrared background is clearly visible by eye. We also create lensing maps with thermal Sunyaev-Zel'dovich contamination removed using a novel cleaning procedure that only slightly degrades the lensing signal-to-noise ratio. The cross-spectrum between the cleaned lensing map and the BOSS CMASS galaxy sample is detected at 10 sigma significance, with an amplitude of A = 1.02 +/- 0.10 relative to the Planck best-fitting Lambda cold dark matter cosmological model with fiducial linear galaxy bias. Our measurement lays the foundation for lensing cross-correlation science with current ACT data and beyond.
  • No Thumbnail Available
    Item
    The Atacama Cosmology Telescope: a measurement of the Cosmic Microwave Background power spectra at 98 and 150 GHz
    (2020) Choi, Steve K.; Hasselfield, Matthew; Ho, Shuay-Pwu Patty; Koopman, Brian; Lungu, Marius; Abitbol, Maximilian H.; Addison, Graeme E.; Ade, Peter A. R.; Aiola, Simone; Alonso, David; Amiri, Mandana; Amodeo, Stefania; Angile, Elio; Austermann, Jason E.; Baildon, Taylor; Battaglia, Nick; Beall, James A.; Bean, Rachel; Becker, Daniel T.; Bond, J. Richard; Bruno, Sarah Marie; Calabrese, Erminia; Calafut, Victoria; Campusano, Luis E.; Carrero, Felipe; Chesmore, Grace E.; Cho, Hsiao-mei; Clark, Susan E.; Cothard, Nicholas F.; Crichton, Devin; Crowley, Kevin T.; Darwish, Omar; Datta, Rahul; Denison, Edward, V; Devlin, Mark J.; Duell, Cody J.; Duff, Shannon M.; Duivenvoorden, Adriaan J.; Dunkley, Jo; Dunner, Rolando; Essinger-Hileman, Thomas; Fankhanel, Max; Ferraro, Simone; Fox, Anna E.; Fuzia, Brittany; Gallardo, Patricio A.; Gluscevic, Vera; Golec, Joseph E.; Grace, Emily; Gralla, Megan; Guan, Yilun; Hall, Kirsten; Halpern, Mark; Han, Dongwon; Hargrave, Peter; Henderson, Shawn; Hensley, Brandon; Hill, J. Colin; Hilton, Gene C.; Hilton, Matt; Hincks, Adam D.; Hlozek, Renee; Hubmayr, Johannes; Huffenberger, Kevin M.; Hughes, John P.; Infante, Leopoldo; Irwin, Kent; Jackson, Rebecca; Klein, Jeff; Knowles, Kenda; Kosowsky, Arthur; Lakey, Vincent; Li, Dale; Li, Yaqiong; Li, Zack; Lokken, Martine; Louis, Thibaut; MacInnis, Amanda; Madhavacheril, Mathew; Maldonado, Felipe; Mallaby-Kay, Maya; Marsden, Danica; Maurin, Loic; McMahon, Jeff; Menanteau, Felipe; Moodley, Kavilan; Morton, Tim; Naess, Sigurd; Namikawa, Toshiya; Nati, Federico; Newburgh, Laura; Nibarger, John P.; Nicola, Andrina; Niemack, Michael D.; Nolta, Michael R.; Orlowski-Sherer, John; Page, Lyman A.; Pappas, Christine G.; Partridge, Bruce; Phakathi, Phumlani; Prince, Heather; Puddu, Roberto; Qu, Frank J.; Rivera, Jesus; Robertson, Naomi; Rojas, Felipe; Salatino, Maria; Schaan, Emmanuel; Schillaci, Alessandro; Schmitt, Benjamin L.; Sehgal, Neelima; Sherwin, Blake D.; Sierra, Carlos; Sievers, Jon; Sifon, Cristobal; Sikhosana, Precious; Simon, Sara; Spergel, David N.; Staggs, Suzanne T.; Stevens, Jason; Storer, Emilie; Sunder, Dhaneshwar D.; Switzer, Eric R.; Thorne, Ben; Thornton, Robert; Trac, Hy; Treu, Jesse; Tucker, Carole; Vale, Leila R.; Van Engelen, Alexander; Van Lanen, Jeff; Vavagiakis, Eve M.; Wagoner, Kasey; Wang, Yuhan; Ward, Jonathan T.; Wollack, Edward J.; Xu, Zhilei; Zago, Fernando; Zhu, Ningfeng
    We present the temperature and polarization angular power spectra of the CMB measured by the Atacama Cosmology Telescope (ACT) from 5400 deg(2) of the 2013-2016 survey, which covers >15000 deg(2) at 98 and 150 GHz. For this analysis we adopt a blinding strategy to help avoid confirmation bias and, related to this, show numerous checks for systematic error done before unblinding. Using the likelihood for the cosmological analysis we constrain secondary sources of anisotropy and foreground emission, and derive a "CMB-only" spectrum that extends to l = 4000. At large angular scales, foreground emission at 150 GHz is similar to 1% of TT and EE within our selected regions and consistent with that found by Planck. Using the same likelihood, we obtain the cosmological parameters for Lambda CDM for the ACT data alone with a prior on the optical depth of tau = 0.065 +/- 0.015. Lambda CDM is a good fit. The best-fit model has a reduced chi(2) of 1.07 (PTE = 0.07) with H-0 = 67.9 +/- 1.5 km/s/Mpc. We show that the lensing BB signal is consistent with Lambda CDM and limit the celestial EB polarization angle to psi(P) = 0.07 degrees +/- 0.09 degrees. We directly cross correlate ACT with Planck and observe generally good agreement but with some discrepancies in TE. All data on which this analysis is based will be publicly released.
  • No Thumbnail Available
    Item
    The Atacama Cosmology Telescope: arcminute-resolution maps of 18 000 square degrees of the microwave sky from ACT 2008-2018 data combined with Planck
    (2020) Naess, Sigurd; Aiola, Simone; Austermann, Jason E.; Battaglia, Nick; Beall, James A.; Becker, Daniel T.; Bond, Richard J.; Calabrese, Erminia; Choi, Steve K.; Cothard, Nicholas F.; Crowley, Kevin T.; Darwish, Omar; Datta, Rahul; Denison, Edward, V; Devlin, Mark; Duell, Cody J.; Duff, Shannon M.; Duivenvoorden, Adriaan J.; Dunkley, Jo; Duenner, Rolando; Fox, Anna E.; Gallardo, Patricio A.; Halpern, Mark; Han, Dongwon; Hasselfield, Matthew; Hill, J. Colin; Hilton, Gene C.; Hilton, Matt; Hincks, Adam D.; Hlozek, Renee; Ho, Shuay-Pwu Patty; Hubmayr, Johannes; Huffenberger, Kevin; Hughes, John P.; Kosowsky, Arthur B.; Louis, Thibaut; Madhavacheril, Mathew S.; McMahon, Jeff; Moodley, Kavilan; Nati, Federico; Nibarger, John P.; Niemack, Michael D.; Page, Lyman; Partridge, Bruce; Salatino, Maria; Schaan, Emmanuel; Schillaci, Alessandro; Schmitt, Benjamin; Sherwin, Blake D.; Sehgal, Neelima; Sifon, Cristobal; Spergel, David; Staggs, Suzanne; Stevens, Jason; Storer, Emilie; Ullom, Joel N.; Vale, Leila R.; Van Engelen, Alexander; Van Lanen, Jeff; Vavagiakis, Eve M.; Wollack, Edward J.; Xu, Zhilei
    This paper presents a maximum-likelihood algorithm for combining sky maps with disparate sky coverage, angular resolution and spatially varying anisotropic noise into a single map of the sky. We use this to merge hundreds of individual maps covering the 2008-2018 ACT observing seasons, resulting in by far the deepest ACT maps released so far. We also combine the maps with the full Planck maps, resulting in maps that have the best features of both Planck and ACT: Planck's nearly white noise on intermediate and large angular scales and ACT's high-resolution and sensitivity on small angular scales. The maps cover over 18 000 square degrees, nearly half the full sky, at 100, 150 and 220 GHz. They reveal 4 000 optically-confirmed clusters through the Sunyaev Zel'dovich effect (SZ) and 18 500 point source candidates at > 5 sigma, the largest single collection of SZ clusters and millimeter wave sources to date. The multi-frequency maps provide millimeter images of nearby galaxies and individual Milky Way nebulae, and even clear detections of several nearby stars. Other anticipated uses of these maps include, for example, thermal SZ and kinematic SZ cluster stacking, CMB cluster lensing and galactic dust science. The method itself has negligible bias. However, due to the preliminary nature of some of the component data sets, we caution that these maps should not be used for precision cosmological analysis. The maps are part of ACT DR5, and will be made available on LAMBDA no later than three months after the journal publication of this article, along with an interactive sky atlas.
  • No Thumbnail Available
    Item
    The Atacama Cosmology Telescope: DR4 maps and cosmological parameters
    (2020) Aiola, Simone; Calabrese, Erminia; Maurin, Loic; Naess, Sigurd; Schmitt, Benjamin L.; Abitbol, Maximilian H.; Addison, Graeme E.; Ade, Peter A. R.; Alonso, David; Amiri, Mandana; Amodeo, Stefania; Angile, Elio; Austermann, Jason E.; Baildon, Taylor; Battaglia, Nick; Beall, James A.; Bean, Rachel; Becker, Daniel T.; Bond, J. Richard; Bruno, Sarah Marie; Calafut, Victoria; Campusano, Luis E.; Carrero, Felipe; Chesmore, Grace E.; Cho, Hsiao-mei; Choi, Steve K.; Clark, Susan E.; Cothard, Nicholas F.; Crichton, Devin; Crowley, Kevin T.; Darwish, Omar; Datta, Rahul; Denison, Edward, V; Devlin, Mark J.; Duell, Cody J.; Duff, Shannon M.; Duivenvoorden, Adriaan J.; Dunkley, Jo; Dunner, Rolando; Essinger-Hileman, Thomas; Fankhanel, Max; Ferraro, Simone; Fox, Anna E.; Fuzia, Brittany; Gallardo, Patricio A.; Gluscevic, Vera; Golec, Joseph E.; Grace, Emily; Gralla, Megan; Guan, Yilun; Hall, Kirsten; Halpern, Mark; Han, Dongwon; Hargrave, Peter; Hasselfield, Matthew; Helton, Jakob M.; Henderson, Shawn; Hensley, Brandon; Hill, J. Colin; Hilton, Gene C.; Hilton, Matt; Hincks, Adam D.; Hlozek, Renee; Ho, Shuay-Pwu Patty; Hubmayr, Johannes; Huffenberger, Kevin M.; Hughes, John P.; Infante, Leopoldo; Irwin, Kent; Jackson, Rebecca; Klein, Jeff; Knowles, Kenda; Koopman, Brian; Kosowsky, Arthur; Lakey, Vincent; Li, Dale; Li, Yaqiong; Li, Zack; Lokken, Martine; Louis, Thibaut; Lungu, Marius; MacInnis, Amanda; Madhavacheril, Mathew; Maldonado, Felipe; Mallaby-Kay, Maya; Marsden, Danica; McMahon, Jeff; Menanteau, Felipe; Moodley, Kavilan; Morton, Tim; Namikawa, Toshiya; Nati, Federico; Newburgh, Laura; Nibarger, John P.; Nicola, Andrina; Niemack, Michael D.; Nolta, Michael R.; Orlowski-Sherer, John; Page, Lyman A.; Pappas, Christine G.; Partridge, Bruce; Phakathi, Phumlani; Pisano, Giampaolo; Prince, Heather; Puddu, Roberto; Qu, Frank J.; Rivera, Jesus; Robertson, Naomi; Rojas, Felipe; Salatino, Maria; Schaan, Emmanuel; Schillaci, Alessandro; Sehgal, Neelima; Sherwin, Blake D.; Sierra, Carlos; Sievers, Jon; Sifon, Cristobal; Sikhosana, Precious; Simon, Sara; Spergel, David N.; Staggs, Suzanne T.; Stevens, Jason; Storer, Emilie; Sunder, Dhaneshwar D.; Switzer, Eric R.; Thorne, Ben; Thornton, Robert; Hy Trac; Treu, Jesse; Tucker, Carole; Vale, Leila R.; Van Engelen, Alexander; Van Lanen, Jeff; Vavagiakis, Eve M.; Wagoner, Kasey; Wang, Yuhan; Ward, Jonathan T.; Wollack, Edward J.; Xu, Zhilei; Zago, Fernando; Zhu, Ningfeng
    We present new arcminute-resolution maps of the Cosmic Microwave Background temperature and polarization anisotropy from the Atacama Cosmology Telescope, using data taken from 2013-2016 at 98 and 150 GHz. The maps cover more than 17,000 deg(2), the deepest 600 deg(2) with noise levels below 10 mu K-arcmin. We use the power spectrum derived from almost 6,000 deg(2) of these maps to constrain cosmology. The ACT data enable a measurement of the angular scale of features in both the divergence-like polarization and the temperature anisotropy, tracing both the velocity and density at last-scattering. From these one can derive the distance to the last-scattering surface and thus infer the local expansion rate, H-0. By combining ACT data with large-scale information from WMAP we measure H-0 = 67.6 +/- 1.1 km/s/Mpc, at 68% confidence, in excellent agreement with the independently-measured Planck satellite estimate (from ACT alone we find H-0 = 67.9 +/- 1.5 km/s/Mpc). The Lambda CDM model provides a good fit to the ACT data, and we find no evidence for deviations: both the spatial curvature, and the departure from the standard lensing signal in the spectrum, are zero to within 1 sigma; the number of relativistic species, the primordial Helium fraction, and the running of the spectral index are consistent with Lambda CDM predictions to within 1.5-2.2 sigma. We compare ACT, WMAP, and Planck at the parameter level and find good consistency; we investigate how the constraints on the correlated spectral index and baryon density parameters readjust when adding CMB large-scale information that ACT does not measure. The DR4 products presented here will be publicly released on the NASA Legacy Archive for Microwave Background Data Analysis.