Probing the Black-Hole-Mass-Galaxy Connection of Active Galaxies Using 2D Galaxy Fitting Techniques on Near-Infrared Images

Active Galactic Nuclei (AGNs) provide a unique opportunity to measure the mass of supermassive black holes located in the centers of their host galaxies. This enables studying the scaling relations between the mass of the black hole and the properties of the host galaxy. In this thesis, we present an investigation of the relationship between black hole masses and the host galaxy bulge and total luminosity for a pilot sample of 15 objects imaged in the near-infrared with the 8m telescope of Gemini North observatory. We perform a 2D decomposition of the host galaxies using the software Galfit and obtain photometric measurements of the components. The high spatial resolution of the Gemini images allows for a detailed study of the different host galaxy components, in particular distinguishing between classical and pseudo-bulges in the presence of a bright AGN point source. In the literature, there is controversy about whether the mass of the black hole scales more closely with classical or pseudo bulges. Shedding light on this issue is crucial to our understanding of the underlying physical driver of the relations. In this study, the improved near-infrared images resulted in very different host galaxy parameters compared to those published in Bennert et al. 2015 based on images from the Sloan Digital Sky Survey. Our findings suggest that the sample of active galaxies reside in galaxies that are over-luminous compared to quiescent galaxies. Furthermore, we find that pseudo bulges are on the black-hole-mass - bulge-luminosity relation. However, for a handful of objects, the Gemini images do not have sufficient resolution to resolve the (pseudo-) bulge. Therefore, follow-up observations with the Hubble Space Telescope are currently underway

Higgsless simulations of cosmological phase transitions and gravitational waves

First-order cosmological phase transitions in the early Universe source sound waves and, subsequently, a background of stochastic gravitational waves. Currently, predictions of these gravitational waves rely heavily on simulations of a Higgs field coupled to the plasma of the early Universe, the former providing the latent heat of the phase transition. Numerically, this is a rather demanding task since several length scales enter the dynamics. From smallest to largest, these are the thickness of the Higgs interface separating the different phases, the shell thickness of the sound waves, and the average bubble size. In this work, we present an approach to perform Higgsless simulations in three dimensions, producing fully nonlinear results, while at the same time removing the hierarchically smallest scale from the lattice. This significantly reduces the complexity of the problem and contributes to making our approach highly efficient. We provide spectra for the produced gravitational waves for various choices of wall velocity and strength of the phase transition, as well as introduce a fitting function for the spectral shape.Comment: 31 pages, 11 figures. V2 includes 2 new appendix and fixed typo in Fig

Gravitational waves from defect-driven phase transitions: domain walls

We discuss the gravitational wave spectrum produced by first-order phase transitions seeded by domain wall networks. This setup is important for many two-step phase transitions as seen for example in the singlet extension of the standard model. Whenever the correlation length of the domain wall network is larger than the typical bubble size, this setup leads to a gravitational wave signal that is shifted to lower frequencies and with an enhanced amplitude compared to homogeneous phase transitions without domain walls. We discuss our results in light of the recent PTA hints for gravitational waves.Comment: 20 pages, 6 figure

The Lick AGN Monitoring Project 2016: Dynamical Modeling of Velocity-Resolved H\b{eta} Lags in Luminous Seyfert Galaxies

We have modeled the velocity-resolved reverberation response of the H\b{eta} broad emission line in nine Seyfert 1 galaxies from the Lick Active Galactic Nucleus (AGN) Monitioring Project 2016 sample, drawing inferences on the geometry and structure of the low-ionization broad-line region (BLR) and the mass of the central supermassive black hole. Overall, we find that the H\b{eta} BLR is generally a thick disk viewed at low to moderate inclination angles. We combine our sample with prior studies and investigate line-profile shape dependence, such as log10(FWHM/{\sigma}), on BLR structure and kinematics and search for any BLR luminosity-dependent trends. We find marginal evidence for an anticorrelation between the profile shape of the broad H\b{eta} emission line and the Eddington ratio, when using the root-mean-square spectrum. However, we do not find any luminosity-dependent trends, and conclude that AGNs have diverse BLR structure and kinematics, consistent with the hypothesis of transient AGN/BLR conditions rather than systematic trends

The Lick AGN Monitoring Project 2016 : dynamical modeling of velocity-resolved Hβ lags in luminous Seyfert galaxies

K.H. acknowledges support from STFC grant ST/R000824/1.We have modeled the velocity-resolved reverberation response of the Hβ broad emission line in nine Seyfert 1 galaxies from the Lick Active Galactic Nucleus (AGN) Monitoring Project 2016 sample, drawing inferences on the geometry and structure of the low-ionization broad-line region (BLR) and the mass of the central supermassive black hole. Overall, we find that the Hβ BLR is generally a thick disk viewed at low to moderate inclination angles. We combine our sample with prior studies and investigate line-profile shape dependence, such as log10(FWHM/σ), on BLR structure and kinematics and search for any BLR luminosity-dependent trends. We find marginal evidence for an anticorrelation between the profile shape of the broad Hβ emission line and the Eddington ratio, when using the rms spectrum. However, we do not find any luminosity-dependent trends, and conclude that AGNs have diverse BLR structure and kinematics, consistent with the hypothesis of transient AGN/BLR conditions rather than systematic trends.Publisher PDFPeer reviewe

The Lick AGN Monitoring Project 2016 : velocity-resolved Hβ lags in luminous Seyfert galaxies

Funding: K.H. acknowledges support from STFC grant ST/R000824/1.We carried out spectroscopic monitoring of 21 low-redshift Seyfert 1 galaxies using the Kast double spectrograph on the 3 m Shane telescope at Lick Observatory from April 2016 to May 2017. Targetingactive galactic nuclei (AGN) with luminosities of λLλ(5100 Å) ≈ 1044 erg s−1 and predicted Hβ lags of∼ 20–30 days or black hole masses of 107–108.5 M⊙, our campaign probes luminosity-dependent trends in broad-line region (BLR) structure and dynamics as well as to improve calibrations for single-epoch estimates of quasar black hole masses. Here we present the first results from the campaign, including Hβ emission-line light curves, integrated Hβ lag times (8–30 days) measured against V -band continuum light curves, velocity-resolved reverberation lags, line widths of the broad Hβ components, and virial black hole mass estimates (107.1–108.1 M⊙). Our results add significantly to the number of existing velocity-resolved lag measurements and reveal a diversity of BLR gas kinematics at moderately high AGN luminosities. AGN continuum luminosity appears not to be correlated with the type of kinematics that its BLR gas may exhibit. Follow-up direct modeling of this dataset will elucidate the detailed kinematics and provide robust dynamical black hole masses for several objects in this sample.Publisher PDFPeer reviewe

Primordiala svarta hål och tidig materiadominans

Primordial black holes (PBHs) are expected to form in the very early universe, and therefore, we could use them to probe pre­BBN times. Astrophysical observations permit the placement of bounds on the abundance of PBHs. Combining these bounds with predictions of PBH formation and the resulting PBH abundances, we explore the possibility to constrain an epoch of early matter domination (MD). For this analysis, we incorporate the recently obtained and most stringent bounds on PBHs from 21 cm observations. We assume density perturbations described by a near­power­law form of the curvature power spectrum consistent with the Planck 2018 results and derive the corresponding PBH mass function using recent results from the literature. To place constraints on an early matter­dominated (MD) epoch, we compare this with up­to­ date bounds on PBHs, adding those from 21 cm astronomy, using a formalism to apply monochromatic constraints to extended mass functions. We find that 21 cm bounds on PBHs may probe early MD if it lasts for a duration of at least ∼ 12 e­folds and ends at a reheating temperature T_min < T_reh ≲ 105.5 GeV, where Tmin depends on the duration of the MD, the spectral index ns, and αs. For optimistic assumptions, our derived limits on the spectral index ns extend into the Planck 2018 67% upper confidence region of n_s = 0.9649 ± 0.0042, nearly reaching its median n_s = 0.9649, if we neglect the running αs. Our bounds on the running α_s show that early MD is incompatible with positive running α_s ≳ 0.Primordiala svarta hål förutsäges ha skapats i det mycket tidiga universum. Ur detta förstår vi att dessa svarta hål ger oss en länk till universums tillstånd under deras skapelse och att vi genom studiet av primordiala svarta hål kan skymta detta tillstånd. Restriktioner på mängden primordiala svarta hål i universum kan beräknas utifrån astrofysiska observationer. Jämförelse av dessa restriktioner med teoretiska förutsägelser av vilka mängder av primordiala svarta hål som skapats vid olika tillstånd medger att vissa tillstånd utesluts. I detta arbete undersöker vi just detta samband och avser etablera huruvida de starkaste restriktionerna på primordiala svarta hål, speciellt från 21 cm observationer av universum, kan utesluta ett kosmologiskt scenario med tidig materiadominans. För att göra detta antar vi att störningar i den annars homogena energidensiteten kan beskrivas med hjälp av ett nästan­storleksoberoende potenssamband vars form ges av resultat från Planck kollaborationen 2018. Givet denna potenslag beräknar vi en form för de primordiala svarta hålens massdistribution medelst resultat från den vetenskapliga litteraturen. Vi jämför sedan dessa förutsägelser med de senaste mängdrestriktionerna på primordiala svarta hål, inkluderat dem från 21 cm observationer, för att erhålla nya begränsningar på tidig materiadominans. Vi tar i beaktande att massdistributionen av primordiala svarta hål inte är monokromatisk, utan utbredd. Resultatet av denna analys är att tidig materiadominans är inom räckhåll för att uteslutas medelst studier av primordiala svarta hål om perioden av materiadominans är längre än ∼ 12 e­folds och att den slutar vid återuppvärmningstemperaturen T_min < T_reh ≲ 10^5.5 GeV, där Tmin beror på hur länge den tidiga materiadominansen varar, på det spektrala indexet ns och det spektrala indexets derivata αs. För optimistiska antaganden äventyrar dessa restriktioner på materiadominans resultat från Planck kollaborationen 2018 i det att det övre konfidensintervallet på det spektrala indexet n_s = 0.9649 ± 0.0042 är exkluderat, och att förändringen av detta index, α_s, inte kan vara positiv då vi låter storleksordningen minska

Primordiala svarta hål och tidig materiadominans

Primordial black holes (PBHs) are expected to form in the very early universe, and therefore, we could use them to probe pre­BBN times. Astrophysical observations permit the placement of bounds on the abundance of PBHs. Combining these bounds with predictions of PBH formation and the resulting PBH abundances, we explore the possibility to constrain an epoch of early matter domination (MD). For this analysis, we incorporate the recently obtained and most stringent bounds on PBHs from 21 cm observations. We assume density perturbations described by a near­power­law form of the curvature power spectrum consistent with the Planck 2018 results and derive the corresponding PBH mass function using recent results from the literature. To place constraints on an early matter­dominated (MD) epoch, we compare this with up­to­ date bounds on PBHs, adding those from 21 cm astronomy, using a formalism to apply monochromatic constraints to extended mass functions. We find that 21 cm bounds on PBHs may probe early MD if it lasts for a duration of at least ∼ 12 e­folds and ends at a reheating temperature T_min < T_reh ≲ 105.5 GeV, where Tmin depends on the duration of the MD, the spectral index ns, and αs. For optimistic assumptions, our derived limits on the spectral index ns extend into the Planck 2018 67% upper confidence region of n_s = 0.9649 ± 0.0042, nearly reaching its median n_s = 0.9649, if we neglect the running αs. Our bounds on the running α_s show that early MD is incompatible with positive running α_s ≳ 0.Primordiala svarta hål förutsäges ha skapats i det mycket tidiga universum. Ur detta förstår vi att dessa svarta hål ger oss en länk till universums tillstånd under deras skapelse och att vi genom studiet av primordiala svarta hål kan skymta detta tillstånd. Restriktioner på mängden primordiala svarta hål i universum kan beräknas utifrån astrofysiska observationer. Jämförelse av dessa restriktioner med teoretiska förutsägelser av vilka mängder av primordiala svarta hål som skapats vid olika tillstånd medger att vissa tillstånd utesluts. I detta arbete undersöker vi just detta samband och avser etablera huruvida de starkaste restriktionerna på primordiala svarta hål, speciellt från 21 cm observationer av universum, kan utesluta ett kosmologiskt scenario med tidig materiadominans. För att göra detta antar vi att störningar i den annars homogena energidensiteten kan beskrivas med hjälp av ett nästan­storleksoberoende potenssamband vars form ges av resultat från Planck kollaborationen 2018. Givet denna potenslag beräknar vi en form för de primordiala svarta hålens massdistribution medelst resultat från den vetenskapliga litteraturen. Vi jämför sedan dessa förutsägelser med de senaste mängdrestriktionerna på primordiala svarta hål, inkluderat dem från 21 cm observationer, för att erhålla nya begränsningar på tidig materiadominans. Vi tar i beaktande att massdistributionen av primordiala svarta hål inte är monokromatisk, utan utbredd. Resultatet av denna analys är att tidig materiadominans är inom räckhåll för att uteslutas medelst studier av primordiala svarta hål om perioden av materiadominans är längre än ∼ 12 e­folds och att den slutar vid återuppvärmningstemperaturen T_min < T_reh ≲ 10^5.5 GeV, där Tmin beror på hur länge den tidiga materiadominansen varar, på det spektrala indexet ns och det spektrala indexets derivata αs. För optimistiska antaganden äventyrar dessa restriktioner på materiadominans resultat från Planck kollaborationen 2018 i det att det övre konfidensintervallet på det spektrala indexet n_s = 0.9649 ± 0.0042 är exkluderat, och att förändringen av detta index, α_s, inte kan vara positiv då vi låter storleksordningen minska

Duets with nature : How natural acoustics affect the experience of performing Nordic herding music in outdoor settings

By employing an approach inspired by affect and theories on natural acoustics, this article explores how and what affects sound propagation outdoors and what role echoes and reverberation has in affective experiences of performing Nordic herding music outdoors. To study this, we traveled to eight summer farms (fäbodar) in Sweden together with seven herding musicians. We measured and described essential data of landscape, soundscape and airscape and instructed the musicians to try their vocal and instrumental sounds in different frequencies and timbres. We also asked them to evaluate their sounds and describe how they experienced the natural acoustics and how these experiences affected how they felt when they sang and played their horns. Putting together their answers with the data drawn from our measurements, the study shows that responses in nature is crucial for a positive experience of calling and playing horns. The results also tells us that when the aim of producing a sound is to reach far, and the musicians experience that they do just that, they experience emotions of joy, empowerment, satisfaction and being “one with nature” in a duet between the musician and the echoes of the forested mountains