Multi-wavelength analysis to constrain the role of AGN in galaxy evolution

It is widely accepted that the formation of stars in galaxies must somehow be regulated to achieve the observed galaxy demographics. In massive galaxies in particular, the supermassive black holes that are known to reside at their centres are the most likely source of this regulation. The growth of these black holes through the accretion of gas releases considerable amounts of energy in the form of radiation and / or bipolar jets of charged particles. During these growth phases they are referred to as `active galactic nuclei' (AGN). This energy has the potential to regulate star formation in the host galaxies, by removing gas through outflows, halting the accretion of new gas onto the galaxy, and/or rendering the gas incapable of forming stars (e.g.\ through heating / turbulence). This is collectively referred to as `AGN feedback'. Around 10~percent of AGN have extreme radio luminosities due to powerful jets which are capable of preventing gas accretion onto the galaxy. However, for the remaining $\sim$90~percent of the AGN population, the so called `radio-quiet' AGN, the physical processes at play are less clear. This thesis targets a sample representative of the majority of AGN, and uses multi-wavelength observations to resolve some of the outstanding questions about how `radio-quiet' AGN transfer energy into their host galaxies, impact the surrounding multi-phase gas and, consequently, impact the evolution of their host galaxies. In the first part of this thesis I study ten local ($z~10^45 erg/s), 'radio-quiet' AGN selected to have powerful ionised gas outflows, combining radio observations (with spatial resolutions up to 20 times better than the pre-existing data), and optical integral field spectroscopy. Jet-like radio emission on ~kpc scales was discovered in 70-80 percent of the sample, and it was revealed that these jets are driving ionised gas outflows in their host galaxies. This challenges the expectation that photon pressure should dominate feedback in these systems, and establishes that jets are playing an important role in the evolution of galaxies even in this 'radio-quiet' regime. I then used observations of the total carbon monoxide emission in nine of the sources studied in the radio to demonstrate that the outflows and jets do not have an immediate, global impact on the total reservoir of molecular, star-forming gas in their host galaxies. Specifically, at least seven of the AGN observed reside in gas-rich, highly star-forming galaxies. Finally, I present the first results on the full Quasar Feedback Survey, expanding the sample studied to 42 targets and removing the pre-selection for known outflows. In this ~four times larger, unbiased sample I showed that radio jet like features are still present in the majority (66 percent) of the sample and found a correlation between radio size and the ionised gas outflow properties, indicative of jet-gas interactions. This work has confirmed a connection between outflows and radio emission, and determined that jets are an important mechanism for driving outflows even in 'radio-quiet' AGN. I also discovered that even in systems with outflows and jets there is no immediate, appreciable impact on the global molecular gas content. These results will require simulations of feedback to be updated, and represent a significant step forward in the quest to form a complete understanding of how galaxies evolve

Multi-wavelength analysis to constrain the role of AGN in galaxy evolution

It is widely accepted that the formation of stars in galaxies must somehow be regulated to achieve the observed galaxy demographics. In massive galaxies in particular, the supermassive black holes that are known to reside at their centres are the most likely source of this regulation. The growth of these black holes through the accretion of gas releases considerable amounts of energy in the form of radiation and / or bipolar jets of charged particles. During these growth phases they are referred to as `active galactic nuclei' (AGN). This energy has the potential to regulate star formation in the host galaxies, by removing gas through outflows, halting the accretion of new gas onto the galaxy, and/or rendering the gas incapable of forming stars (e.g.\ through heating / turbulence). This is collectively referred to as `AGN feedback'. Around 10~percent of AGN have extreme radio luminosities due to powerful jets which are capable of preventing gas accretion onto the galaxy. However, for the remaining $\sim$90~percent of the AGN population, the so called `radio-quiet' AGN, the physical processes at play are less clear. This thesis targets a sample representative of the majority of AGN, and uses multi-wavelength observations to resolve some of the outstanding questions about how `radio-quiet' AGN transfer energy into their host galaxies, impact the surrounding multi-phase gas and, consequently, impact the evolution of their host galaxies. In the first part of this thesis I study ten local ($z~10^45 erg/s), 'radio-quiet' AGN selected to have powerful ionised gas outflows, combining radio observations (with spatial resolutions up to 20 times better than the pre-existing data), and optical integral field spectroscopy. Jet-like radio emission on ~kpc scales was discovered in 70-80 percent of the sample, and it was revealed that these jets are driving ionised gas outflows in their host galaxies. This challenges the expectation that photon pressure should dominate feedback in these systems, and establishes that jets are playing an important role in the evolution of galaxies even in this 'radio-quiet' regime. I then used observations of the total carbon monoxide emission in nine of the sources studied in the radio to demonstrate that the outflows and jets do not have an immediate, global impact on the total reservoir of molecular, star-forming gas in their host galaxies. Specifically, at least seven of the AGN observed reside in gas-rich, highly star-forming galaxies. Finally, I present the first results on the full Quasar Feedback Survey, expanding the sample studied to 42 targets and removing the pre-selection for known outflows. In this ~four times larger, unbiased sample I showed that radio jet like features are still present in the majority (66 percent) of the sample and found a correlation between radio size and the ionised gas outflow properties, indicative of jet-gas interactions. This work has confirmed a connection between outflows and radio emission, and determined that jets are an important mechanism for driving outflows even in 'radio-quiet' AGN. I also discovered that even in systems with outflows and jets there is no immediate, appreciable impact on the global molecular gas content. These results will require simulations of feedback to be updated, and represent a significant step forward in the quest to form a complete understanding of how galaxies evolve

The Wide Integral Field Infrared Spectrograph: Commissioning Results and On-sky Performance

We have recently commissioned a novel infrared ($0.9-1.7$ $\mu$m) integral field spectrograph (IFS) called the Wide Integral Field Infrared Spectrograph (WIFIS). WIFIS is a unique instrument that offers a very large field-of-view (50$^{\prime\prime}$ x 20$^{\prime\prime}$) on the 2.3-meter Bok telescope at Kitt Peak, USA for seeing-limited observations at moderate spectral resolving power. The measured spatial sampling scale is $\sim1\times1^{\prime\prime}$ and its spectral resolving power is $R\sim2,500$ and $3,000$ in the $zJ$ ($0.9-1.35$ $\mu$m) and $H_{short}$ ($1.5-1.7$ $\mu$m) modes, respectively. WIFIS's corresponding etendue is larger than existing near-infrared (NIR) IFSes, which are mostly designed to work with adaptive optics systems and therefore have very narrow fields. For this reason, this instrument is specifically suited for studying very extended objects in the near-infrared such as supernovae remnants, galactic star forming regions, and nearby galaxies, which are not easily accessible by other NIR IFSes. This enables scientific programs that were not originally possible, such as detailed surveys of a large number of nearby galaxies or a full accounting of nucleosynthetic yields of Milky Way supernova remnants. WIFIS is also designed to be easily adaptable to be used with larger telescopes. In this paper, we report on the overall performance characteristics of the instrument, which were measured during our commissioning runs in the second half of 2017. We present measurements of spectral resolving power, image quality, instrumental background, and overall efficiency and sensitivity of WIFIS and compare them with our design expectations. Finally, we present a few example observations that demonstrate WIFIS's full capability to carry out infrared imaging spectroscopy of extended objects, which is enabled by our custom data reduction pipeline.Comment: Published in the Proceedings of SPIE Astronomical Telescopes and Instrumentation 2018. 17 pages, 13 figure

MAGIC upper limits on the very high energy emission from GRBs

The fast repositioning system of the MAGIC Telescope has allowed during its first data cycle, between 2005 and the beginning of year 2006, observing nine different GRBs as possible sources of very high energy gammas. These observations were triggered by alerts from Swift, HETE-II, and Integral; they started as fast as possible after the alerts and lasted for several minutes, with an energy threshold varying between 80 and 200 GeV, depending upon the zenith angle of the burst. No evidence for gamma signals was found, and upper limits for the flux were derived for all events, using the standard analysis chain of MAGIC. For the bursts with measured redshift, the upper limits are compatible with a power law extrapolation, when the intrinsic fluxes are evaluated taking into account the attenuation due to the scattering in the Metagalactic Radiation Field (MRF).Comment: 25 pages, 9 figures, final version accepted by ApJ. Changet title to "MAGIC upped limits on the VERY high energy emission from GRBs", re-organized chapter with description of observation, removed non necessaries figures, added plot of effective area depending on zenith angle, added an appendix explaining the upper limit calculation, added some reference

First cosmology results using SNe Ia from the dark energy survey: analysis, systematic uncertainties, and validation

International audienceWe present the analysis underpinning the measurement of cosmological parameters from 207 spectroscopically classified type Ia supernovae (SNe Ia) from the first three years of the Dark Energy Survey Supernova Program (DES-SN), spanning a redshift range of 0.01

Cosmic Shear in Harmonic Space from the Dark Energy Survey Year 1 Data: Compatibility with Configuration Space Results

We perform a cosmic shear analysis in harmonic space using the first year of data collected by the Dark Energy Survey (DES-Y1). We measure the cosmic weak lensing shear power spectra using the Metacalibration catalogue and perform a likelihood analysis within the framework of CosmoSIS. We set scale cuts based on baryonic effects contamination and model redshift and shear calibration uncertainties as well as intrinsic alignments. We adopt as fiducial covariance matrix an analytical computation accounting for the mask geometry in the Gaussian term, including non-Gaussian contributions. A suite of 1200 lognormal simulations is used to validate the harmonic space pipeline and the covariance matrix. We perform a series of stress tests to gauge the robustness of the harmonic space analysis. Finally, we use the DES-Y1 pipeline in configuration space to perform a similar likelihood analysis and compare both results, demonstrating their compatibility in estimating the cosmological parameters $S_8$, $\sigma_8$ and $\Omega_m$. The methods implemented and validated in this paper will allow us to perform a consistent harmonic space analysis in the upcoming DES data.Comment: 16 pages, 11 figures. This version matches the published on

Dark Energy Survey Year 1 results: cosmological constraints from galaxy clustering and weak lensing

We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg 2 of griz imaging data from the first year of the Dark Energy Survey (DES Y1). We combine three two-point functions: (i) the cosmic shear correlation function of 26 million source galaxies in four redshift bins, (ii) the galaxy angular autocorrelation function of 650,000 luminous red galaxies in five redshift bins, and (iii) the galaxy-shear cross-correlation of luminous red galaxy positions and source galaxy shears. To demonstrate the robustness of these results, we use independent pairs of galaxy shape, photometric redshift estimation and validation, and likelihood analysis pipelines. To prevent confirmation bias, the bulk of the analysis was carried out while blind to the true results; we describe an extensive suite of systematics checks performed and passed during this blinded phase. The data are modeled in flat Λ CDM and w CDM cosmologies, marginalizing over 20 nuisance parameters, varying 6 (for Λ CDM) or 7 (for w CDM) cosmological parameters including the neutrino mass density and including the 457 × 457 element analytic covariance matrix. We find consistent cosmological results from these three two-point functions, and from their combination obtain S 8 ≡σ 8 (Ω m /0.3) 0.5 =0.783 +0.021 −0.025 and Ω m =0.264 +0.032 −0.019 for Λ CDM for w CDM, we find S 8 =0.794 +0.029 −0.027, Ω m =0.279 +0.043 −0.022, and w=−0.80 +0.20 −0.22 at 68% CL. The precision of these DES Y1 results rivals that from the Planck cosmic microwave background measurements, allowing a comparison of structure in the very early and late Universe on equal terms. Although the DES Y1 best-fit values for S 8 and Ω m are lower than the central values from Planck

Examining the effectiveness of general practitioner and nurse promotion of electronic cigarettes versus standard care for smoking reduction and abstinence in hardcore smokers with smoking-related chronic disease:protocol for a randomised controlled trial

BACKGROUND: Despite the clear harm associated with smoking tobacco, many people with smoking-related chronic diseases or serious mental illnesses (SMI) are unwilling or unable to stop smoking. In many cases, these smokers have tried and exhausted all methods to stop smoking and yet clinicians are repeatedly mandated to offer them during routine consultations. Providing nicotine through electronic cigarettes (e-cigarettes) may reduce the adverse health consequences associated with tobacco smoking, but these are not currently offered. The aim of this study is to examine the feasibility, acceptability and effectiveness of general practitioners (GPs) and nurses delivering a brief advice intervention on e-cigarettes and offering an e-cigarette starter pack and patient support resources compared with standard care in smokers with smoking-related chronic diseases or SMI who are unwilling to stop smoking. METHODS/DESIGN: This is an individually randomised, blinded, two-arm trial. Smokers with a smoking-related chronic condition or SMI with no intention of stopping smoking will be recruited through primary care registers. Eligible participants will be randomised to one of two groups if they decline standard care for stopping smoking: a control group who will receive no additional support beyond standard care; or an intervention group who will receive GP or nurse-led brief advice about e-cigarettes, an e-cigarette starter pack with accompanying practical support booklet, and telephone support from experienced vapers and online video tutorials. The primary outcome measures will be smoking reduction, measured through changes in cigarettes per day and 7-day point-prevalence abstinence at 2 months. Secondary outcomes include smoking reduction, 7-day point-prevalence abstinence and prolonged abstinence at 8 months. Other outcomes include patient recruitment and follow-up, patient uptake and use of e-cigarettes, nicotine intake, contamination of randomisation and practitioner adherence to the delivery of the intervention. Qualitative interviews will be conducted in a subsample of practitioners, patients and the vape team to garner their reactions to the programme. DISCUSSION: This is the first randomised controlled trial to investigate whether e-cigarette provision alongside a brief intervention delivered by practitioners leads to reduced smoking and abstinence among smokers with smoking-related chronic diseases or SMI. TRIAL REGISTRATION: ISRCTN registry, ISRCTN59404712. Registered 28/11/17