We present the discovery of K2-113b, a dense hot-Jupiter discovered using photometry from Campaig... more We present the discovery of K2-113b, a dense hot-Jupiter discovered using photometry from Campaign 8 of the Kepler-2 (K2) mission and high-resolution spectroscopic follow up obtained with the FEROS spectrograph. The planet orbits a V=13.68 solar analogue in a P=5.81760^+0.00003_-0.00003 day orbit, has a radius of 0.93^+0.10_-0.07R_J and a mass of 1.29^+0.13_-0.14M_J. With a density of 1.97^+0.60_-0.53 gr/cm^3, the planet is among the densest systems known having masses below 2 M_J and T_eq > 1000, and is just above the temperature limit at which inflation mechanisms are believed to start being important. Based on its mass and radius, we estimate that K2-113b should have a heavy element content on the order of ∼ 110 M_⊕ or greater.
Giant, long-period exoplanets are vital to unveiling the underlying physics of planet formation a... more Giant, long-period exoplanets are vital to unveiling the underlying physics of planet formation and evolution. They are true relics of the planet formation process, maintaining their orbital and compositional properties, and their radii evolve without external irradiation, providing rich and unique data for planet evolution models. We present the Warm gIaNts with tEss collaboration (WINE), which is at the forefront of detecting, confirming, and characterizing transiting long-period giant exoplanets from TESS. Our systematic search has given rise to hundreds of transiting giant candidates with periods of 10 to hundreds of days, which is considerably enhancing and complementing the scientific output of the TESS mission. We introduce our efficient ground-based photometric and radial-velocity follow-up, which has helped confirm several tens of these candidates, including some of the most eccentric transiting long-period planets discovered to date, which are excellent candidates for futu...
We present a detection of the Sunyaev-Zel'dovich (SZ) decrement associated with the Luminous Red ... more We present a detection of the Sunyaev-Zel'dovich (SZ) decrement associated with the Luminous Red Galaxy (LRG) sample of the Sloan Digital Sky Survey. The SZ data come from 148 GHz maps of the equatorial region made by the Atacama Cosmology Telescope (ACT). The LRG sample is divided by luminosity into four bins, and estimates for the central SZ temperature decrement are calculated through a stacking process. We detect and account for a bias of the SZ signal due to weak radio sources. We use numerical simulations to relate the observed decrement to Y 200 and clustering properties to relate the galaxy luminosity to halo mass. We also use a relation between brightest cluster galaxy luminosity and cluster mass based on stacked gravitational lensing measurements to estimate the characteristic halo masses. The masses are found to be around 10 14 M ⊙ .
We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TO... more We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TOI-954 (TIC 44792534, V = 10.343, T = 9.78) observed in TESS sectors 4 and 5 and one transiting the G dwarf K2-329 (EPIC 246193072, V = 12.70, K = 10.67) observed in K2 campaigns 12 and 19. We confirm and characterize these two planets with a variety of ground-based archival and follow-up observations, including photometry, reconnaissance spectroscopy, precise radial velocity, and high-resolution imaging. Combining all available data, we find that TOI-954 b has a radius of-+ R 0.852 0.062 0.053 J and a mass of-+ 0.174 0.017 0.018 M J and is in a 3.68 day orbit, while K2-329 b has a radius of-+ R 0.774 0.024 0.026 J and a mass of-+ 0.260 0.022 0.020 M J and is in a 12.46 day orbit. As TOI-954 b is 30 times more irradiated than K2-329 b but more or less the same size, these two planets provide an opportunity to test whether irradiation leads to inflation of Saturn-mass planets and contribute to future comparative studies that explore Saturn-mass planets at contrasting points in their lifetimes.
We present a statistical analysis of the millimeter-wavelength properties of 1.4 GHz-selected sou... more We present a statistical analysis of the millimeter-wavelength properties of 1.4 GHz-selected sources and a detection of the Sunyaev-Zel'dovich effect associated with the halos that host them. We stack data at 148, 218 and 277 GHz from the Atacama Cosmology Telescope at the positions of a large sample of radio AGN selected at 1.4 GHz. The thermal Sunyaev-Zel'dovich (SZ) effect associated with the halos that host the AGN is detected at the 5σ level through its spectral signature, representing a statistical detection of the SZ effect in some of the lowest mass halos (average M 200 ≈ 10 13 M h −1 70) studied to date. The relation between the SZ effect and mass (based on weak lensing measurements of radio galaxies) is consistent with that measured by Planck for local bright galaxies. In the context of galaxy evolution models, this study confirms that galaxies with radio AGN also typically support hot gaseous halos. Adding Herschel observations allows us to show that the SZ signal is not significantly contaminated by dust emission. Finally, we analyze the contribution of radio sources to the angular power spectrum of the cosmic microwave background.
We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TO... more We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TOI-954 (TIC 44792534, $ V = 10.343 $, $ T = 9.78 $) observed in TESS Sectors 4 & 5, and one transiting the G dwarf EPIC 246193072 ($ V = 12.70 $, $ K = 10.67 $) observed in K2 Campaigns 12 & 19. We confirm and characterize these two planets with a variety of ground-based archival and follow-up observations, including photometry, reconnaissance spectroscopy, precise radial velocity, and high-resolution imaging. Combining all available data, we find that TOI-954 b has a radius of $0.852_{-0.062}^{+0.053} \, R_{\mathrm{J}}$ and a mass of $0.174_{-0.017}^{+0.018} \, M_{\mathrm{J}}$ and is in a 3.68 d orbit, while EPIC 246193072 b has a radius of $0.774_{-0.024}^{+0.026} \, R_{\mathrm{J}}$ and a mass of $0.260_{-0.022}^{+0.020} \, M_{\mathrm{J}}$ and is in a 12.46 d orbit. As TOI-954 b is 30 times more irradiated than EPIC 246193072 b but is more or less of the same size, these two planets pro...
Monthly Notices of the Royal Astronomical Society, 2019
We report the discovery of the 1.008-d, ultrashort period (USP) super-Earth HD 213885b (TOI-141b)... more We report the discovery of the 1.008-d, ultrashort period (USP) super-Earth HD 213885b (TOI-141b) orbiting the bright (V = 7.9) star HD 213885 (TOI-141, TIC 403224672), detected using photometry from the recently launched TESS mission. Using FEROS, HARPS, and CORALIE radial velocities, we measure a precise mass of 8.8 ± 0.6 M⊕ for this 1.74 ± 0.05 R⊕ exoplanet, which provides enough information to constrain its bulk composition – similar to Earth’s but enriched in iron. The radius, mass, and stellar irradiation of HD 213885b are, given our data, very similar to 55 Cancri e, making this exoplanet a good target to perform comparative exoplanetology of short period, highly irradiated super-Earths. Our precise radial velocities reveal an additional 4.78-d signal which we interpret as arising from a second, non-transiting planet in the system, HD 213885c, whose minimum mass of 19.9 ± 1.4 M⊕ makes it consistent with being a Neptune-mass exoplanet. The HD 213885 system is very interesting ...
This paper presents the results of an exploratory study that analyzes the main factors of the dec... more This paper presents the results of an exploratory study that analyzes the main factors of the decision making process of recruitment and selection of strategic positions for companies located in Santiago of Chile, in the Metropolitan Region of Chile. The methodology developed uses AHP Multi-criteria concepts, addressing the major theoretical foundations of this methodology. The results of a survey of organizations in Santiago city, in order to obtain the similarities and the most relevant factors for the recruitment and selection of strategic positions, are presented, allowing the establishment of an exploratory common pattern for the process.
Monthly Notices of the Royal Astronomical Society, 2020
The Cosmic Microwave Background (CMB) has been measured over a wide range of multipoles. Experime... more The Cosmic Microwave Background (CMB) has been measured over a wide range of multipoles. Experiments with arcminute resolution like the Atacama Cosmology Telescope (ACT) have contributed to the measurement of primary and secondary anisotropies, leading to remarkable scientific discoveries. Such findings require careful data selection in order to remove poorly behaved detectors and unwanted contaminants. The current data classification methodology used by ACT relies on several statistical parameters that are assessed and fine-tuned by an expert. This method is highly time-consuming and band or season-specific, which makes it less scalable and efficient for future CMB experiments. In this work, we propose a supervised machine learning model to classify detectors of CMB experiments. The model corresponds to a deep convolutional neural network. We tested our method on real ACT data, using the 2008 season, 148 GHz, as training set with labels provided by the ACT data selection software. ...
We report the discovery of BD+20594b, a high density sub-Neptune exoplanet, made using photometry... more We report the discovery of BD+20594b, a high density sub-Neptune exoplanet, made using photometry from Campaign 4 of the two-wheeled Kepler (K2) mission, ground-based radial velocity follow-up from HARPS and high resolution lucky and adaptive optics imaging obtained using AstraLux and MagAO, respectively. The host star is a bright (V = 11.04, K s = 9.37), slightly metal poor ([Fe/H]= −0.15 ± 0.05 dex) solar analogue located at 152.1 +9.7 −7.4 pc from Earth, for which we find a radius of R * = 0.928 +0.055 −0.040 R ⊙ and a mass of M * = 0.961 +0.032 −0.029 M ⊙. A joint analysis of the K2 photometry and HARPS radial velocities reveal that the planet is in a ≈ 42 day orbit around its host star, has a radius of 2.23 +0.14 −0.11 R ⊕ , and a mass of 16.3 +6.0 −6.1 M ⊕. Although the data at hand puts the planet in the region of the mass-radius diagram where we could expect planets with a pure rock (i.e. magnesium silicate) composition using two-layer models (i.e., between rock/iron and rock/ice compositions), we discuss more realistic three-layer composition models which can explain the high density of the discovered exoplanet. The fact that the planet lies in the boundary between "possibly rocky" and "non-rocky" exoplanets, makes it an interesting planet for future RV follow-up.
This paper analyses the relationship between innovation and employment for Spanish manufacturing ... more This paper analyses the relationship between innovation and employment for Spanish manufacturing firms with data from Panel of Technological Innovation between 2004 to 2010. Following the model developed by Harrison et al. (2008), the results provide empirical evidence about the existence of different patterns in the impacts of process and product innovations on firms' employment for the pre-crisis period and during the economic crisis.
We report on measurements of the cosmic microwave background (CMB) and celestial polarization at ... more We report on measurements of the cosmic microwave background (CMB) and celestial polarization at 146 GHz made with the Atacama Cosmology Telescope Polarimeter (ACTPol) in its first three months of observing. Four regions of sky covering a total of 270 square degrees were mapped with an angular resolution of 1.3. The map noise levels in the four regions are between 11 and 17 µK-arcmin. We present TT, TE, EE, TB, EB, and BB power spectra from three of these regions. The observed E-mode polarization power spectrum, displaying six acoustic peaks in the range 200 < < 3000, is an excellent fit to the prediction of the best-fit cosmological models from WMAP9+ACT and Planck data. The polarization power spectrum, which mainly reflects primordial plasma velocity perturbations, provides an independent determination of cosmological parameters consistent with those based on the temperature power spectrum, which results mostly from primordial density perturbations. We find that without masking any point sources in the EE data at < 9000, the Poisson tail of the EE power spectrum due to polarized point sources has an amplitude less than 2.4 µK 2 at = 3000 at 95% confidence. Finally, we report that the Crab Nebula, an important polarization calibration source at microwave frequencies, has 8.7% polarization with an angle of 150.7 • ± 0.6 • when smoothed with a 5 Gaussian beam.
We present constraints on the primordial power spectrum of adiabatic fluctuations using data from... more We present constraints on the primordial power spectrum of adiabatic fluctuations using data from the 2008 Southern Survey of the Atacama Cosmology Telescope (ACT) in combination with measurements from the Wilkinson Microwave Anisotropy Probe and a prior on the Hubble constant. The angular resolution of ACT provides sensitivity to scales beyond = 1000 for resolution of multiple peaks in the primordial temperature power spectrum, which enables us to probe the primordial power spectrum of adiabatic scalar perturbations with wavenumbers up to k 0.2 Mpc −1. We find no evidence for deviation from power-law fluctuations over two decades in scale. Matter fluctuations inferred from the primordial temperature power spectrum evolve over cosmic time and can be used to predict the matter power spectrum at late times; we illustrate the overlap of the matter power inferred from cosmic microwave background measurements (which probe the power spectrum in the linear regime) with existing probes of galaxy clustering, cluster abundances, and weak-lensing constraints on the primordial power. This highlights the range of scales probed by current measurements of the matter power spectrum.
We present measurements of the cosmic microwave background (CMB) power spectrum made by the Ataca... more We present measurements of the cosmic microwave background (CMB) power spectrum made by the Atacama Cosmology Telescope at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. Our results clearly show the second through the seventh acoustic peaks in the CMB power spectrum. The measurements of these higher-order peaks provide an additional test of the ΛCDM cosmological model. At > 3000, we detect power in excess of the primary anisotropy spectrum of the CMB. At lower multipoles 500 < < 3000, we find evidence for gravitational lensing of the CMB in the power spectrum at the 2.8σ level. We also detect a low level of Galactic dust in our maps, which demonstrates that we can recover known faint, diffuse signals.
We present a detection of the Sunyaev-Zel'dovich (SZ) decrement associated with the Luminous Red ... more We present a detection of the Sunyaev-Zel'dovich (SZ) decrement associated with the Luminous Red Galaxy (LRG) sample of the Sloan Digital Sky Survey. The SZ data come from 148 GHz maps of the equatorial region made by the Atacama Cosmology Telescope (ACT). The LRG sample is divided by luminosity into four bins, and estimates for the central SZ temperature decrement are calculated through a stacking process. We detect and account for a bias of the SZ signal due to weak radio sources. We use numerical simulations to relate the observed decrement to Y 200 and clustering properties to relate the galaxy luminosity to halo mass. We also use a relation between brightest cluster galaxy luminosity and cluster mass based on stacked gravitational lensing measurements to estimate the characteristic halo masses. The masses are found to be around 10 14 M ⊙ .
Este seminario tiene por objetivo caracterizar las principales etapas del proceso emprendedor chi... more Este seminario tiene por objetivo caracterizar las principales etapas del proceso emprendedor chileno durante los noventa. Mediante el uso de técnicas estadísticas y econométricas, se analizan los factores que influyen sobre el éxito de las empresas, divididos de acuerdo a la fuente ...
We present the discovery of K2-113b, a dense hot-Jupiter discovered using photometry from Campaig... more We present the discovery of K2-113b, a dense hot-Jupiter discovered using photometry from Campaign 8 of the Kepler-2 (K2) mission and high-resolution spectroscopic follow up obtained with the FEROS spectrograph. The planet orbits a V=13.68 solar analogue in a P=5.81760^+0.00003_-0.00003 day orbit, has a radius of 0.93^+0.10_-0.07R_J and a mass of 1.29^+0.13_-0.14M_J. With a density of 1.97^+0.60_-0.53 gr/cm^3, the planet is among the densest systems known having masses below 2 M_J and T_eq > 1000, and is just above the temperature limit at which inflation mechanisms are believed to start being important. Based on its mass and radius, we estimate that K2-113b should have a heavy element content on the order of ∼ 110 M_⊕ or greater.
Giant, long-period exoplanets are vital to unveiling the underlying physics of planet formation a... more Giant, long-period exoplanets are vital to unveiling the underlying physics of planet formation and evolution. They are true relics of the planet formation process, maintaining their orbital and compositional properties, and their radii evolve without external irradiation, providing rich and unique data for planet evolution models. We present the Warm gIaNts with tEss collaboration (WINE), which is at the forefront of detecting, confirming, and characterizing transiting long-period giant exoplanets from TESS. Our systematic search has given rise to hundreds of transiting giant candidates with periods of 10 to hundreds of days, which is considerably enhancing and complementing the scientific output of the TESS mission. We introduce our efficient ground-based photometric and radial-velocity follow-up, which has helped confirm several tens of these candidates, including some of the most eccentric transiting long-period planets discovered to date, which are excellent candidates for futu...
We present a detection of the Sunyaev-Zel'dovich (SZ) decrement associated with the Luminous Red ... more We present a detection of the Sunyaev-Zel'dovich (SZ) decrement associated with the Luminous Red Galaxy (LRG) sample of the Sloan Digital Sky Survey. The SZ data come from 148 GHz maps of the equatorial region made by the Atacama Cosmology Telescope (ACT). The LRG sample is divided by luminosity into four bins, and estimates for the central SZ temperature decrement are calculated through a stacking process. We detect and account for a bias of the SZ signal due to weak radio sources. We use numerical simulations to relate the observed decrement to Y 200 and clustering properties to relate the galaxy luminosity to halo mass. We also use a relation between brightest cluster galaxy luminosity and cluster mass based on stacked gravitational lensing measurements to estimate the characteristic halo masses. The masses are found to be around 10 14 M ⊙ .
We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TO... more We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TOI-954 (TIC 44792534, V = 10.343, T = 9.78) observed in TESS sectors 4 and 5 and one transiting the G dwarf K2-329 (EPIC 246193072, V = 12.70, K = 10.67) observed in K2 campaigns 12 and 19. We confirm and characterize these two planets with a variety of ground-based archival and follow-up observations, including photometry, reconnaissance spectroscopy, precise radial velocity, and high-resolution imaging. Combining all available data, we find that TOI-954 b has a radius of-+ R 0.852 0.062 0.053 J and a mass of-+ 0.174 0.017 0.018 M J and is in a 3.68 day orbit, while K2-329 b has a radius of-+ R 0.774 0.024 0.026 J and a mass of-+ 0.260 0.022 0.020 M J and is in a 12.46 day orbit. As TOI-954 b is 30 times more irradiated than K2-329 b but more or less the same size, these two planets provide an opportunity to test whether irradiation leads to inflation of Saturn-mass planets and contribute to future comparative studies that explore Saturn-mass planets at contrasting points in their lifetimes.
We present a statistical analysis of the millimeter-wavelength properties of 1.4 GHz-selected sou... more We present a statistical analysis of the millimeter-wavelength properties of 1.4 GHz-selected sources and a detection of the Sunyaev-Zel'dovich effect associated with the halos that host them. We stack data at 148, 218 and 277 GHz from the Atacama Cosmology Telescope at the positions of a large sample of radio AGN selected at 1.4 GHz. The thermal Sunyaev-Zel'dovich (SZ) effect associated with the halos that host the AGN is detected at the 5σ level through its spectral signature, representing a statistical detection of the SZ effect in some of the lowest mass halos (average M 200 ≈ 10 13 M h −1 70) studied to date. The relation between the SZ effect and mass (based on weak lensing measurements of radio galaxies) is consistent with that measured by Planck for local bright galaxies. In the context of galaxy evolution models, this study confirms that galaxies with radio AGN also typically support hot gaseous halos. Adding Herschel observations allows us to show that the SZ signal is not significantly contaminated by dust emission. Finally, we analyze the contribution of radio sources to the angular power spectrum of the cosmic microwave background.
We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TO... more We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TOI-954 (TIC 44792534, $ V = 10.343 $, $ T = 9.78 $) observed in TESS Sectors 4 & 5, and one transiting the G dwarf EPIC 246193072 ($ V = 12.70 $, $ K = 10.67 $) observed in K2 Campaigns 12 & 19. We confirm and characterize these two planets with a variety of ground-based archival and follow-up observations, including photometry, reconnaissance spectroscopy, precise radial velocity, and high-resolution imaging. Combining all available data, we find that TOI-954 b has a radius of $0.852_{-0.062}^{+0.053} \, R_{\mathrm{J}}$ and a mass of $0.174_{-0.017}^{+0.018} \, M_{\mathrm{J}}$ and is in a 3.68 d orbit, while EPIC 246193072 b has a radius of $0.774_{-0.024}^{+0.026} \, R_{\mathrm{J}}$ and a mass of $0.260_{-0.022}^{+0.020} \, M_{\mathrm{J}}$ and is in a 12.46 d orbit. As TOI-954 b is 30 times more irradiated than EPIC 246193072 b but is more or less of the same size, these two planets pro...
Monthly Notices of the Royal Astronomical Society, 2019
We report the discovery of the 1.008-d, ultrashort period (USP) super-Earth HD 213885b (TOI-141b)... more We report the discovery of the 1.008-d, ultrashort period (USP) super-Earth HD 213885b (TOI-141b) orbiting the bright (V = 7.9) star HD 213885 (TOI-141, TIC 403224672), detected using photometry from the recently launched TESS mission. Using FEROS, HARPS, and CORALIE radial velocities, we measure a precise mass of 8.8 ± 0.6 M⊕ for this 1.74 ± 0.05 R⊕ exoplanet, which provides enough information to constrain its bulk composition – similar to Earth’s but enriched in iron. The radius, mass, and stellar irradiation of HD 213885b are, given our data, very similar to 55 Cancri e, making this exoplanet a good target to perform comparative exoplanetology of short period, highly irradiated super-Earths. Our precise radial velocities reveal an additional 4.78-d signal which we interpret as arising from a second, non-transiting planet in the system, HD 213885c, whose minimum mass of 19.9 ± 1.4 M⊕ makes it consistent with being a Neptune-mass exoplanet. The HD 213885 system is very interesting ...
This paper presents the results of an exploratory study that analyzes the main factors of the dec... more This paper presents the results of an exploratory study that analyzes the main factors of the decision making process of recruitment and selection of strategic positions for companies located in Santiago of Chile, in the Metropolitan Region of Chile. The methodology developed uses AHP Multi-criteria concepts, addressing the major theoretical foundations of this methodology. The results of a survey of organizations in Santiago city, in order to obtain the similarities and the most relevant factors for the recruitment and selection of strategic positions, are presented, allowing the establishment of an exploratory common pattern for the process.
Monthly Notices of the Royal Astronomical Society, 2020
The Cosmic Microwave Background (CMB) has been measured over a wide range of multipoles. Experime... more The Cosmic Microwave Background (CMB) has been measured over a wide range of multipoles. Experiments with arcminute resolution like the Atacama Cosmology Telescope (ACT) have contributed to the measurement of primary and secondary anisotropies, leading to remarkable scientific discoveries. Such findings require careful data selection in order to remove poorly behaved detectors and unwanted contaminants. The current data classification methodology used by ACT relies on several statistical parameters that are assessed and fine-tuned by an expert. This method is highly time-consuming and band or season-specific, which makes it less scalable and efficient for future CMB experiments. In this work, we propose a supervised machine learning model to classify detectors of CMB experiments. The model corresponds to a deep convolutional neural network. We tested our method on real ACT data, using the 2008 season, 148 GHz, as training set with labels provided by the ACT data selection software. ...
We report the discovery of BD+20594b, a high density sub-Neptune exoplanet, made using photometry... more We report the discovery of BD+20594b, a high density sub-Neptune exoplanet, made using photometry from Campaign 4 of the two-wheeled Kepler (K2) mission, ground-based radial velocity follow-up from HARPS and high resolution lucky and adaptive optics imaging obtained using AstraLux and MagAO, respectively. The host star is a bright (V = 11.04, K s = 9.37), slightly metal poor ([Fe/H]= −0.15 ± 0.05 dex) solar analogue located at 152.1 +9.7 −7.4 pc from Earth, for which we find a radius of R * = 0.928 +0.055 −0.040 R ⊙ and a mass of M * = 0.961 +0.032 −0.029 M ⊙. A joint analysis of the K2 photometry and HARPS radial velocities reveal that the planet is in a ≈ 42 day orbit around its host star, has a radius of 2.23 +0.14 −0.11 R ⊕ , and a mass of 16.3 +6.0 −6.1 M ⊕. Although the data at hand puts the planet in the region of the mass-radius diagram where we could expect planets with a pure rock (i.e. magnesium silicate) composition using two-layer models (i.e., between rock/iron and rock/ice compositions), we discuss more realistic three-layer composition models which can explain the high density of the discovered exoplanet. The fact that the planet lies in the boundary between "possibly rocky" and "non-rocky" exoplanets, makes it an interesting planet for future RV follow-up.
This paper analyses the relationship between innovation and employment for Spanish manufacturing ... more This paper analyses the relationship between innovation and employment for Spanish manufacturing firms with data from Panel of Technological Innovation between 2004 to 2010. Following the model developed by Harrison et al. (2008), the results provide empirical evidence about the existence of different patterns in the impacts of process and product innovations on firms' employment for the pre-crisis period and during the economic crisis.
We report on measurements of the cosmic microwave background (CMB) and celestial polarization at ... more We report on measurements of the cosmic microwave background (CMB) and celestial polarization at 146 GHz made with the Atacama Cosmology Telescope Polarimeter (ACTPol) in its first three months of observing. Four regions of sky covering a total of 270 square degrees were mapped with an angular resolution of 1.3. The map noise levels in the four regions are between 11 and 17 µK-arcmin. We present TT, TE, EE, TB, EB, and BB power spectra from three of these regions. The observed E-mode polarization power spectrum, displaying six acoustic peaks in the range 200 < < 3000, is an excellent fit to the prediction of the best-fit cosmological models from WMAP9+ACT and Planck data. The polarization power spectrum, which mainly reflects primordial plasma velocity perturbations, provides an independent determination of cosmological parameters consistent with those based on the temperature power spectrum, which results mostly from primordial density perturbations. We find that without masking any point sources in the EE data at < 9000, the Poisson tail of the EE power spectrum due to polarized point sources has an amplitude less than 2.4 µK 2 at = 3000 at 95% confidence. Finally, we report that the Crab Nebula, an important polarization calibration source at microwave frequencies, has 8.7% polarization with an angle of 150.7 • ± 0.6 • when smoothed with a 5 Gaussian beam.
We present constraints on the primordial power spectrum of adiabatic fluctuations using data from... more We present constraints on the primordial power spectrum of adiabatic fluctuations using data from the 2008 Southern Survey of the Atacama Cosmology Telescope (ACT) in combination with measurements from the Wilkinson Microwave Anisotropy Probe and a prior on the Hubble constant. The angular resolution of ACT provides sensitivity to scales beyond = 1000 for resolution of multiple peaks in the primordial temperature power spectrum, which enables us to probe the primordial power spectrum of adiabatic scalar perturbations with wavenumbers up to k 0.2 Mpc −1. We find no evidence for deviation from power-law fluctuations over two decades in scale. Matter fluctuations inferred from the primordial temperature power spectrum evolve over cosmic time and can be used to predict the matter power spectrum at late times; we illustrate the overlap of the matter power inferred from cosmic microwave background measurements (which probe the power spectrum in the linear regime) with existing probes of galaxy clustering, cluster abundances, and weak-lensing constraints on the primordial power. This highlights the range of scales probed by current measurements of the matter power spectrum.
We present measurements of the cosmic microwave background (CMB) power spectrum made by the Ataca... more We present measurements of the cosmic microwave background (CMB) power spectrum made by the Atacama Cosmology Telescope at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. Our results clearly show the second through the seventh acoustic peaks in the CMB power spectrum. The measurements of these higher-order peaks provide an additional test of the ΛCDM cosmological model. At > 3000, we detect power in excess of the primary anisotropy spectrum of the CMB. At lower multipoles 500 < < 3000, we find evidence for gravitational lensing of the CMB in the power spectrum at the 2.8σ level. We also detect a low level of Galactic dust in our maps, which demonstrates that we can recover known faint, diffuse signals.
We present a detection of the Sunyaev-Zel'dovich (SZ) decrement associated with the Luminous Red ... more We present a detection of the Sunyaev-Zel'dovich (SZ) decrement associated with the Luminous Red Galaxy (LRG) sample of the Sloan Digital Sky Survey. The SZ data come from 148 GHz maps of the equatorial region made by the Atacama Cosmology Telescope (ACT). The LRG sample is divided by luminosity into four bins, and estimates for the central SZ temperature decrement are calculated through a stacking process. We detect and account for a bias of the SZ signal due to weak radio sources. We use numerical simulations to relate the observed decrement to Y 200 and clustering properties to relate the galaxy luminosity to halo mass. We also use a relation between brightest cluster galaxy luminosity and cluster mass based on stacked gravitational lensing measurements to estimate the characteristic halo masses. The masses are found to be around 10 14 M ⊙ .
Este seminario tiene por objetivo caracterizar las principales etapas del proceso emprendedor chi... more Este seminario tiene por objetivo caracterizar las principales etapas del proceso emprendedor chileno durante los noventa. Mediante el uso de técnicas estadísticas y econométricas, se analizan los factores que influyen sobre el éxito de las empresas, divididos de acuerdo a la fuente ...
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