Morphological Demographics of Galaxies at z ∼ 10–16: Log-normal Size Distribution and Exponential Profiles Consistent with the Disk Formation Scenario

Galaxy evolution is complicated. Throughout their lifetimes, galaxies are subject to an amalgamation of astrophysical and cosmological processes that direct the growth of their stellar masses, the transformation of their morphologies, and the cessation of their star formation. The variable action of these processes begets a diverse population of galaxies, which exhibit a variety of brightnesses, colours, shapes, and sizes, among myriad other features. Many of these features are bimodally distributed, which has led to the general acceptance of a simple empirical paradigm of galaxy evolution. However, connecting this diversity among galaxies with the array of processes that are involved in their evolution, and constraining the relative influences of each of these processes, requires that several features are analysed simultaneously. This has been enabled by the recent advent of machine learning techniques, which are capable of extracting scientifically useful information from complicated, multi-dimensional datasets, to astronomy and astrophysics. Unsupervised machine learning techniques, free from the requirement for pre-labelled training data, are especially well suited to the exploration of the data structures of galaxy samples in multi-dimensional feature spaces. This thesis assesses the use of clustering, an unsupervised machine learning technique, for the research of galaxy evolution. Clustering is first tested on a well-characterised sample of galaxies from the GAMA survey. Galaxies are represented in five dimensions by a set of intrinsic astrophysical features. Use of a unique cluster evaluation framework enables the robust identification of reproducible and astrophysically meaningful clustering structures via the k-means method. Outcomes consisting of two, three, five, and six clusters are deemed stable, and form a hierarchical structure that agrees well with established notions of the galaxy bimodality. The two- and three-cluster outcomes are dominated in their structures by the stellar masses, colours, and star formation activity of galaxies, with Sersic indices and half-light radii becoming important for the five- and six-cluster outcomes. Clusters also exhibit broad correspondence with detailed morphological classifications, and it is suggested that the inclusion of additional morphological features might improve this correspondence further. The five- and six-cluster outcomes indicate the differential role of environment in the evolution of galaxies with intermediate colours. This cluster evaluation framework is then applied for the validation of the cosmological, hydrodynamical EAGLE simulations against the GAMA survey. Outcomes consisting of seven and five clusters respectively, determined using the same five features for both samples, are selected for analysis. These outcomes produce an agreement score of Vₐ = 0.76, indicating broad, overall agreement, but differences in their substructures. These differences include discrepancies in the growth of the central bulges of galaxies along the star-forming main sequence, an over-abundance of low-mass, bulge-dominated, star-forming galaxies in the EAGLE sample, and a subpopulation of high-mass, disc-dominated, star-forming galaxies in the EAGLE sample that is not present in the GAMA sample. These differences are attributed to the resolution of EAGLE, and to an active galactic nucleus feedback prescription that is not sufficiently effective in EAGLE. Finally, clustering is used to compare samples of galaxies at low (z ~ 0.06; GSWLC-2) and intermediate (z ~ 0.67; VIPERS) redshifts, in order to examine the evolution of subpopulations of galaxies. Galaxies are clustered in a nine-dimensional feature space defined by a series of ultraviolet-through-near-infrared colours using the Subspace Expectation-Maximisation algorithm, which includes iterative dimensionality reduction. The algorithm models both samples using seven clusters: four containing mostly star-forming galaxies, and three containing mostly passive galaxies. Both sets of star-forming clusters form clear morphological sequences, capturing the gradual internally-driven growth of galaxy bulges at both epochs. At high stellar masses, this growth is linked with quenching. However, it is only at low redshifts that additional, environmental processes appear to be involved in the evolution of low-mass passive galaxies. The results of this thesis demonstrate the utility of clustering as a method with which to analyse the large galaxy samples that are anticipated from next-generation surveys, and with which to facilitate the multi-dimensional comparison of cosmological galaxy simulations with observations. Clustering is robustly able to identify astrophysically meaningful substructures in complex, multi-dimensional feature spaces, and these substructures may readily be interpreted with respect to the evolutionary contexts of the galaxies that they encompass.

Based on the spectroscopic and shear catalogs for SDSS galaxies in the local Universe, we compared optically selected active galactic nuclei (AGNs) with control star-forming and quiescent galaxies on galactic and inter-halo scales, and larger. We find that AGNs are preferentially found in two specific stages of galaxy evolution: in the starburst and ‘green valley’ phases. We also find that the stellar population of their host galaxies is quite independent of stellar mass, which is not the case for more typical galaxies. Combining galaxy-galaxy lensing and galaxy clustering on large scales, we measured the mass of AGN host halos. The typical halo mass is about 1012 h−1 M⊙, similar to the characteristic mass in the stellar mass-halo mass relation (SHMR). For a given stellar mass, AGN host galaxies and star-forming galaxies share the same SHMR, while quiescent galaxies have more massive halos. Clustering analyses on halo scales reveals that AGNs are surrounded by a larger number of satellites (with stellar mass down to 1/1000 of the mass of the central galaxy) than star-forming galaxies and that galaxies with a greater stellar velocity dispersion have a greater number of satellites. The number of satellites also increase with halo mass, reaching unity around 1012 h−1 M⊙. Our results suggest a scenario in which the interaction of the central galaxy with the satellites triggers an early episode of starburst and AGN activity, followed by multiple AGN cycles driven by the non-axisymmetric structure produced by the interaction. The feedback from the starburst and AGN reduces the amount of cold gas for fueling the central black hole, producing a characteristic halo mass scale, that is, ∼1012 h−1 M⊙, where the AGN fraction peaks.

We study the link between the kinematic-morphology of galaxies, as inferred from integral-field stellar kinematics, and their relation between mass and star formation rate. Our sample consists of ∼3200 galaxies with integral-field spectroscopic data from the MaNGA survey (Mapping Nearby Galaxies at Apache Point Observatory) with available determinations of their effective stellar angular momentum within the half-light radius $\lambda _{R_e}$. We find that for star-forming galaxies, namely along the star formation main sequence (SFMS), the $\lambda _{R_e}$ values remain large and almost unchanged over about two orders of magnitude in stellar mass, with the exception of the lowest masses $\mathcal {M}_{\star }\lesssim 2\times 10^{9} \, \mathcal {M}_{\odot }$, where $\lambda _{R_e}$ slightly decreases. The SFMS is dominated by spiral galaxies with small bulges. Below the SFMS, but above the characteristic stellar mass $\mathcal {M}_{\rm crit}\approx 2\times 10^{11} \, \mathcal {M}_{\odot }$, there is a sharp decrease in $\lambda _{R_e}$ with decreasing star formation rate (SFR): massive galaxies well below the SFMS are mainly slow-rotator early-type galaxies, namely genuinely spheroidal galaxies without discs. Below the SFMS and below $\mathcal {M}_{\rm crit}$ the decrease of $\lambda _{R_e}$ with decreasing SFR becomes modest or nearly absent: low-mass galaxies well below the SFMS, are fast-rotator early-type galaxies, and contain fast-rotating stellar discs like their star-forming counterparts. We also find a small but clear environmental dependence for the massive galaxies: in the mass range $10^{10.9}\!-\!10^{11.5} \, \mathcal {M}_{\odot }$, galaxies in rich groups or denser regions or classified as central galaxies have lower values of $\lambda _{R_e}$. While no environmental dependence is found for galaxies of lower mass. We discuss how the above results can be understood as due to the different star formation and mass assembly histories of galaxies with varying mass.

Galaxies separate into passive and star-forming galaxies, where star-forming galaxies show a tight correlation between stellar mass and star formation rate (SFR), referred to as the star forming main sequence. In this thesis, we have measured the average galaxy star formation rate – stellar mass relation out to z~5 in the COSMOS (Cosmic Evolution Survey) field. This survey includes deep radio observations taken as part of the VLA-COSMOS 3 GHz large program that provide a dust-unbiased view of star-formation. To measure SFRs over a wide range of galaxy masses, including galaxies too faint to be detected individually, we employed a stacking analysis on the 3 GHz data. We found a flattening of the star-forming main sequence at high masses that can be explained by the increasing fraction of bulge-dominated galaxies which follow a shallower SFR – stellar mass relation than disk-dominated galaxies. As bulges grow more prominent in the low-redshift galaxy population, the flattening of the main sequence becomes more significant. We found that galaxy environment, probed by X-ray-groups and local galaxy number density, has no significant effect on the shape of the star-forming main sequence at z>0.3. We have compared SFRs derived from publicly available mid-infrared (MIR), far-infrared (FIR), radio, and ultraviolet (UV) photometry for massive star-forming galaxies selected consistently at z~0 and z~0.7. We probed the dust properties of these massive disk galaxies by analysing how their UV luminosity depends on galaxy inclination. By comparing our observed trends with radiative transfer model predictions we constrained the average opacity and clumpiness of the dust. We found that UV attenuation has increased between z~0 and z~0.7 by a factor of 3.5. A higher fraction of clumpy dust around nascent star-forming regions can explain the substantial UV attenuation at z~0.7. If the gas and dust geometry at high-redshift are significantly different than inferred from our current models, this would have significant implications for our SFR calibrations relying on the UV and IR emission from galaxies. Reproducing the spatial distribution of galaxy components like stellar mass, newly formed stars, dust, metals, and gas will be a key objective for future theories of galaxy evolution.

Using data from the MOSFIRE Deep Evolution Field (MOSDEF) survey, we present a census of active galactic nucleus (AGN)–driven ionized outflows in a sample of 159 AGNs at 1.4 ≤ z ≤ 3.8. The sample spans AGN bolometric luminosities of 1044–47 erg s−1 and includes both quiescent and star-forming galaxies extending across 3 orders of magnitude in stellar mass. We identify and characterize outflows from the Hβ, [O iii], Hα, and [N ii] emission line spectra. We detect outflows in 17% of the AGNs, seven times more often than in a mass-matched sample of inactive galaxies in MOSDEF. The outflows are fast and galaxy-wide, with velocities of ∼400–3500 km s and spatial extents of 0.3–11.0 kpc. The incidence of outflows among AGNs is independent of the stellar mass of the host galaxy, with outflows detected in both star-forming and quiescent galaxies. This suggests that outflows exist across different phases in galaxy evolution. We investigate relations between outflow kinematic, spatial, and energetic properties and both AGN and host galaxy properties. Our results show that AGN-driven outflows are widespread in galaxies along the star-forming main sequence. The mass-loading factors of the outflows are typically 0.1–1 and increase with AGN luminosity, capable of exceeding unity at . In these more luminous sources, the ionized outflow alone is likely sufficient to regulate star formation and, when combined with outflowing neutral and molecular gas, may be able to quench star formation in their host galaxies.

We study the evidence for a connection between active galactic nuclei (AGN) fueling and star formation by investigating the relationship between the X-ray luminosities of AGN and the star formation rates (SFRs) of their host galaxies. We identify a sample of 309 AGN with $10^{41}<L_\mathrm{X}<10^{44} $ erg s$^{-1}$ at $0.2 < z < 1.2$ in the PRIMUS redshift survey. We find AGN in galaxies with a wide range of SFR at a given $L_X$. We do not find a significant correlation between SFR and the observed instantaneous $L_X$ for star forming AGN host galaxies. However, there is a weak but significant correlation between the mean $L_\mathrm{X}$ and SFR of detected AGN in star forming galaxies, which likely reflects that $L_\mathrm{X}$ varies on shorter timescales than SFR. We find no correlation between stellar mass and $L_\mathrm{X}$ within the AGN population. Within both populations of star forming and quiescent galaxies, we find a similar power-law distribution in the probability of hosting an AGN as a function of specific accretion rate. Furthermore, at a given stellar mass, we find a star forming galaxy $\sim2-3$ more likely than a quiescent galaxy to host an AGN of a given specific accretion rate. The probability of a galaxy hosting an AGN is constant across the main sequence of star formation. These results indicate that there is an underlying connection between star formation and the presence of AGN, but AGN are often hosted by quiescent galaxies.

We investigate the relationship between environment and star formation main sequence (the relationship between stellar mass and star formation rate) to shed new light on the effects of the environments on star-forming galaxies. We use the large VLA-COSMOS 3 GHz catalogue that consist of star-forming galaxies (SFGs) and active galactic nuclei (AGN) in three different environments (field, filament, cluster) and for different galaxy types. We examine for the first time a comparative analysis for the distribution of SFGs with respect to the star formation main sequence (MS) consensus region from the literature, taking into account galaxy environment and using radio selected sample at 0.1 ≤ z ≤ 1.2 drawn from one of the deepest COSMOS radio surveys. We find that, as observed previously, SFRs increase with redshift independent on the environments. Furthermore, we observe that SFRs versus M* relation is flat in all cases, irrespective of the redshift and environments.

In this paper, we present data from 72 low-redshift, hard X-ray selected active galactic nucleus (AGN) taken from the Swift–BAT 58 month catalogue. We utilize spectral energy distribution fitting to the optical to infrared photometry in order to estimate host galaxy properties. We compare this observational sample to a volume- and flux-matched sample of AGN from the Evolution and Assembly of GaLaxies and their Environments (EAGLE) hydrodynamical simulations in order to verify how accurately the simulations can reproduce observed AGN host galaxy properties. After correcting for the known +0.2 dex offset in the SFRs between EAGLE and previous observations, we find agreement in the star formation rate (SFR) and X-ray luminosity distributions; however, we find that the stellar masses in EAGLE are 0.2–0.4 dex greater than the observational sample, which consequently leads to lower specific star formation rates (sSFRs). We compare these results to our previous study at high redshift, finding agreement in both the observations and simulations, whereby the widths of sSFR distributions are similar (∼0.4–0.6 dex) and the median of the SFR distributions lie below the star-forming main sequence by ∼0.3–0.5 dex across all samples. We also use EAGLE to select a sample of AGN host galaxies at high and low redshift and follow their characteristic evolution from z = 8 to z = 0. We find similar behaviour between these two samples, whereby star formation is quenched when the black hole goes through its phase of most rapid growth. Utilizing EAGLE we find that 23 per cent of AGN selected at z ∼ 0 are also AGN at high redshift, and that their host galaxies are among the most massive objects in the simulation. Overall, we find EAGLE reproduces the observations well, with some minor inconsistencies (∼0.2 dex in stellar masses and ∼0.4 dex in sSFRs).

ABSTRACTWe investigate the relationship between the star formation rate (SFR), stellar mass (M*), and molecular gas mass ($M_{\mathrm{ H}_2}$) for local star-forming galaxies. We further investigate these relationships for high-z (z = 1–3) galaxies and for the hosts of a local sample of active galactic nuclei (AGN). We explore which of these dependencies are intrinsic and which are an indirect byproduct by employing partial correlation coefficients and random forest regression. We find that for local star-forming galaxies, high-z galaxies, and AGN host galaxies, the Schmidt–Kennicutt (SK) relation (between $M_{\mathrm{ H}_2}$ and SFR) and the molecular gas main sequence (MGMS; between $M_{\mathrm{ H}_2}$ and M*) are intrinsic primary relations, while the relationship between M* and SFR, i.e. the star-forming main sequence (SFMS), is an indirect byproduct of the former two. Hence the SFMS is not a fundamental scaling relation for local or high-z galaxies. We find evidence for both the evolution of the MGMS and SK relation over cosmic time, where, at a given stellar mass, the higher the redshift, the greater the molecular gas mass and the star formation efficiency. We offer a parametrization of both the MGMS and SK relation’s evolution with redshift, showing how they combine to form the observed evolution of the SFMS. In addition, we find that the local AGN host galaxies follow an AGN–MGMS relation (as well as an AGN–SK relation), where the MGMS is offset to lower $M_{\mathrm{ H}_2}$ for a given M* compared to local star-forming galaxies.

The scatter of the spatially resolved star formation main sequence (SFMS) is investigated in order to reveal signatures about the processes of galaxy formation and evolution. We have assembled a sample of 355 nearby galaxies with spatially resolved Hα and mid-infrared fluxes from the Survey for Ionized Neutral Gas in Galaxies and the Wide-field Infrared Survey Explorer, respectively. We examine the impact of various star formation rate (SFR) and stellar mass transformations on the SFMS. Ranging from 106 to 1011.5 M ⊙ and derived from color to mass-to-light ratio methods for mid-infrared bands, the stellar masses are internally consistent within their range of applicability and inherent systematic errors; a constant mass-to-light ratio also yields representative stellar masses. The various SFR estimates show intrinsic differences and produce noticeable vertical shifts in the SFMS, depending on the timescales and physics encompassed by the corresponding tracer. SFR estimates appear to break down on physical scales below 500 pc. We also examine the various sources of scatter in the spatially resolved SFMS and find morphology does not play a significant role. We identify three unique tracks across the SFMS by individual galaxies, delineated by a critical stellar mass density of log( ) ∼ 7.5. Below this scale, the SFMS shows no clear trend and is likely driven by local, stochastic internal processes. Above this scale, all spatially resolved galaxies have comparable SFMS slopes but exhibit two different behaviors, resulting likely from the rate of mass accretion at the center of the galaxy.

We investigate the relation between galaxy structure and star formation rate (SFR) in a sample of $\sim 2.9\times 10^{4}$ central galaxies with $z\lt 0.0674$ and axial ratios $b/a\gt 0.5$. The star-forming main sequence (SFMS) shows a bend around the stellar mass of $M_\ast \le {}M_c=2\times 10^{10}{}{\rm M}_{\odot }$. At $M_\ast \le {}M_c$, the SFMS follows a power-law $\text{SFR}\propto {}M_\ast ^{0.85}$, while at higher masses it flattens. $M_c$ corresponds to a dark matter halo mass of $M_\text{vir}\sim {}10^{11.8}{\rm M}_{\odot }$ where virial shocks occurs. Some galaxy structure (e.g. half-light radius, $R_e$) exhibits a non-monotonic dependence across the SFMS at a fixed $M_\ast$. We find $\text{SFR}\propto {R_e^{-0.28}}$ at fixed $M_\ast$, consistent with the global Kennicutt–Schmidt (KS) law. This finding suggests that galaxy sizes contribute to the scatter of the SFMS. However, at $M_\ast \gt M_c$ the relationship between SFR and $R_e$ diminishes. Low-mass galaxies above the mean of the SFMS have smaller radii, exhibit compact and centrally concentrated profiles resembling green valley (GV) and quiescent galaxies at the same mass, and have higher $M_{\text{H}_2}{/}M_\rm{H\,{\small I}}$. Conversely, those below the SFMS exhibit larger radii, lower densities, have no GV or quiescent counterparts at their mass and have lower $M_{\text{H}_2}/M_\rm{H\,{\small I}}$. The above data suggest two pathways for quenching low-mass galaxies, $M_\ast \le {}M_c$: a fast one that changes the morphology on the SFMS and a slow one that does not. Above $M_c$, galaxies below the SFMS resemble GV and quiescent galaxies structurally, implying that they undergo a structural transformation already within the SFMS. For these massive galaxies, CG are strongly bimodal, with SFMS galaxies exhibiting negative colour gradients, suggesting most star formation occurs in their outskirts, maintaining them within the SFMS.

We map the co-eval growth of galaxies and their central supermassive black holes in detail by measuring the incidence of Active Galactic Nuclei (AGN) in galaxies as a function of star formation rate (SFR) and redshift (to z~4). We combine large galaxy samples with deep Chandra X-ray imaging to measure the probability distribution of specific black hole accretion rates (LX relative to stellar mass) and derive robust AGN fractions and average specific accretion rates. First, we consider galaxies along the main sequence of star formation. We find a linear correlation between the average SFR and both the AGN fraction and average specific accretion rate across a wide range in stellar mass ($M_* \sim 10^{8.5-11.5}M_\odot$) and to at least z~2.5, indicating that AGN in main-sequence galaxies are driven by the stochastic accretion of cold gas. We also consider quiescent galaxies and find significantly higher AGN fractions than predicted, given their low SFRs, indicating that AGN in quiescent galaxies are fuelled by additional mechanisms (e.g. stellar winds). Next, we bin galaxies according to their SFRs relative to the main sequence. We find that the AGN fraction is significantly elevated for galaxies that are still star-forming but with SFRs below the main sequence, indicating further triggering mechanisms enhance AGN activity within these sub-main-sequence galaxies. We also find that the incidence of high-accretion-rate AGN is enhanced in starburst galaxies and evolves more mildly with redshift than within the rest of the galaxy population, suggesting mergers play a role in driving AGN activity in such high-SFR galaxies.

Context. It is now well known that certain massive galaxies undergo enormous enhancements in their star formation rate (SFR) when they undergo major mergers. These enhancements can be as high as 100 times the SFR of unperturbed galaxies of the same stellar mass. Previous works have found that the size of this boost in star formation (SF) is related to the morphology of and the proximity to the companion. The same trend has also been observed for the fraction of active galactic nuclei (AGN), where galaxies that are closer together tend to have higher AGN fractions. Aims. We aim to analyse the SF enhancement and AGN fraction evolution during the merger process by using a more timeline-like merger sequence. Additionally, we aim to determine the relation between the SF enhancement in mergers and the morphology of the galaxies involved. Methods. Taking advantage of the stellar masses (M*) and SFRs of the ∼600 nearby isolated mergers obtained in our previous study, we calculated the distance of each of our galaxies from the star-forming main sequence (MS; specific SFR (sSFR)/sSFRMS), which werefer to as the SF mode. We then analysed how the SF mode varies during the merger process as a function of morphology and M*. Additionally, we analysed the AGN content of our mergers, using multiple diagnostics based on emission line ratios and WISE colours. Results. We observed that, overall, merging galaxies show an SF mode that is governed by their morphology. Spirals typically show high SF mode values, while highly disturbed (HD) galaxies are generally even more enhanced (median values of +0.8 dex and +1.08 dex above the MS, respectively). In contrast, elliptical and lenticular galaxies show the lowest SF modes, as expected. However, even they show SF enhancement compared to their unperturbed counterparts. For example, their median SF mode is just within the 1-sigma scatter of the MS, and this can occur even before the galaxies have coalesced. We observed a trend for the SF mode to gradually increase with increasing merger stage. We did not find a clear dependency of the observed AGN fraction on the merger stage for the majority of our classification methods. Conclusions. We find mergers can significantly enhance SF in galaxies of all morphologies. For early-type galaxies, this could suggest that some gas was present prior to the merger, which may be triggered to form stars by the tidal interaction. As the SF enhancement continues throughout the merger process, this suggests that the enhancement may be a long-lived event, contrary to the short starbursts seen in some models.

Context. Galaxy evolution has been studied by interpreting the spectral energy distribution of galaxies using spectral synthesis codes. This method has been crucial in discovering different pillars of modern galaxy evolution theories. However, this analysis was mostly carried out using spectral synthesis codes that are purely stellar, that is, they assume that the nebular contribution to the total continuum is negligible. The code FADO is the first publicly available population spectral synthesis tool that treats the contribution from ionised gas to the observed emission self-consistently. This is expected to have a particularly strong effect in star-forming (SF) galaxies. Aims. We study the impact of the nebular contribution on the determination of the star formation rate (SFR), stellar mass, and consequent effect on the star-forming main sequence (SFMS) at low redshift. Methods. We applied FADO to the spectral database of the SDSS to derive the physical properties of galaxies. As a comparison, we used the data in the MPA-JHU catalogue, which contains the properties of SDSS galaxies derived without the nebular contribution. We selected a sample of SF galaxies with Hα and Hβ flux measurements, and we corrected the fluxes for the nebular extinction through the Balmer decrement. We then calculated the Hα luminosity to estimate the SFR. Then, by combining the stellar mass and SFR estimates from FADO and MPA-JHU, the SFMS was obtained. Results. The Hα flux estimates are similar between FADO and MPA-JHU. Because the Hα flux was used as tracer of the SFR, FADO and MPA-JHU agree in their SFR. The stellar mass estimates are slightly higher for FADO than for MPA-JHU on average. However, considering the uncertainties, the differences are negligible. With similar SFR and stellar mass estimates, the derived SFMS is also similar between FADO and MPA-JHU. Conclusions. Our results show that for SDSS normal SF galaxies, the additional modelling of the nebular contribution does not affect the retrieved fluxes and consequentially also does not influence SFR estimators based on the extinction-corrected Hα luminosity. For the stellar masses, the results point to the same conclusion. These results are a consequence of the fact that the vast majority of normal SF galaxies in the SDSS have a low nebular contribution. However, the obtained agreement might only hold for local SF galaxies, but higher-redshift galaxies might show different physical properties when FADO is used. This would then be an effect of the expected increased nebular contribution.

We present the Advanced Camera for Surveys Active Galactic Nuclei (ACS-AGN) Catalog, a catalog of 2585 active galactic nucleus (AGN) host galaxies that are at redshifts 0.2 &lt; z &lt; 2.5 and that were imaged with the Hubble Space Telescope’s Advanced Camera for Surveys (ACS). Using the ACS General Catalog (ACS-GC) as our initial sample, we select an AGN subsample using Spitzer and Chandra data along with their respective established AGN selection criteria. We then gather further multiwavelength photometric data in order to construct spectral energy distributions (SEDs). Using these SEDs, we are able to derive multiple AGN and host galaxy properties, such as star formation rate (SFR), AGN luminosity, stellar mass, and nuclear column density. From these data, we show that AGN host galaxies tend to lie below the star-forming main sequence, with X-ray-selected AGN host galaxies being more offset than IR-selected AGN host galaxies. This suggests that there is some process, possibly negative feedback, in AGN host galaxies causing decreased star formation. We also demonstrate that there is a positive trend between the SFR and AGN luminosity in AGN host galaxies, in individual redshift bins, and across all redshift bins, and that both are correlated with the stellar mass of their galaxies. This points toward an underlying link between the stellar mass, stellar growth, and supermassive black hole growth in a galaxy.