H{\alpha} Imaging of Nearby Seyfert Host Galaxies

We used narrowband interference filters with the CCD imaging camera on the Nickel 1.0 meter telescope at Lick Observatory to observe 31 nearby (z < 0.03) Seyfert galaxies in the 12 {\mu}m Active Galaxy Sample. We obtained pure emission line images of each galaxy in order to separate H{\alpha} emission from the nucleus from that of the host galaxy. The extended H{\alpha} emission is expected to be powered by newly formed hot stars, and correlates well with other indicators of current star formation in these galaxies: 7.7 {\mu}m PAH, far-infrared, and radio luminosity. Relative to what would be expected from recent star formation, there is a 0.8 dex excess of radio emission in our Seyfert galaxies. The nuclear H{\alpha} luminosity is dominated by the AGN, and is correlated with the hard X-ray luminosity. There is an upward offset of 1 dex in this correlation for the Seyfert 1s due to a strong contribution from the Broad Line Region. We found a correlation between star formation rate and AGN luminosity. In spite of selection effects, we concluded that the absence of bright Seyfert nuclei in galaxies with low SFRs is real, albeit only weakly significant. We used our measured spatial distributions of H{\alpha} emission to determine what these Seyfert galaxies would look like when observed through fixed apertures at high redshifts. Although all would be detectable emission line galaxies at any redshift, most would appear dominated by HII region emission. Only the most luminous AGN would still be identified at z~0.3.Comment: 13 pages, 11 figures, accepted for publication in Ap

Pengaruh Belanja Publik daan Pertumbuhan Ekonomi Terhadap Tingkat Kemiskinan di Provinsi Jawa Timur, Periode 2002-2013

Penelitian ini merupakan replikasi model hasil publikasi penelitian Yacoub dan Adelia (2011). Penelitian ini bertujuan untuk mengetahui dan menganalisis pengaruh belanja publik dan pertumbuhan ekonomi terhadap tingkat kemiskinan di Jawa Timur. Pengelolahan data dilakukan dengan menggunakan Ordinary Least Square (OLS) yaitu metode Time series dengan software Eviews 6. Data diperoleh secara tidak langsung yaitu melalui pengolahan data-data atau infollllasi yang telah ada di Jawa Timur. Hasil Penelitian ini menunjukkan adanya pengaruh yang besar dari belanja publik dan pertumbuhan ekonomi terhadap tingkat kemiskinan. Namun pengaruh yang diberikan oleh belanja publik dan pertumbuhan ekonomi tidak signifikan atau tidak secara nyata terhadap tingkat kemiskinan. Hal ini disebabkan dari besar anggaran belanja publik yang didapat dari anggaran APBD dalam belanja langsung masih terbagi menjadi 2 (dua) bagian, yaitu belanja aparatur dan pelayanan publik. Dimana penganggaran yang dapat dirasakan oleh masyarakat secara langsung ialah belanja publik. Sedangkan pada pertumbuhan ekonomi disebabkan oleh dampak yang ditimbulkan oleh variabel tersebut yang lebih mengarah pada long-term. Sehingga pertumbuhan ekonomi memiliki kemungkinan tidak mempengaruhi secara langsung tingkat kemiskinan

Leveraging the Rest-Ultraviolet and Rest-Optical Spectra of Galaxies at 2 < z < 3

Galaxies at the peak of cosmic star formation (2 &lt; z &lt; 3) are fundamentally different from local galaxies, in terms of the properties of their massive stellar populations and physical conditions in the interstellar medium (ISM). This thesis presents a detailed analysis of the stellar and nebular properties of high-redshift galaxies, using the rest-frame UV and rest-frame optical spectra of galaxies from the Keck Baryonic Structure Survey (KBSS), a large, targeted spectroscopic survey of galaxies at 2 &lt; z &lt; 3. Chapter 2 compares inferences of dust attenuation, star formation, and metallicity from strong nebular emission lines, the far-UV continuum, and spectral energy distribution (SED) fits. These results indicate that the majority of high-redshift galaxies display different dust properties than those at low redshift, and that the assumption of a dust attenuation curve can dramatically change inferred properties such as star formation rates (SFRs). I find that SFRs estimated using different methods only agree under specific combinations of assumptions, and caution that SFR calibrations established in the local Universe do not apply at higher redshifts. Chapter 3 utilizes rest-UV absorption lines to study the outflow kinematics of high-redshift galaxies. I compare several velocity metrics used in the literature, and search for correlations between outflow velocity and galaxy properties. These results are consistent with the picture of winds driven by momentum injected into the ISM by stellar feedback. I confirm that large-scale outflows are ubiquitous at high redshift due to these galaxies' high SFRs and compact sizes. Finally, Chapter 4 analyzes the systematic uncertainties involved in fitting stellar population synthesis (SPS) models to rest-UV spectra as well as the full SEDs of galaxies. I quantify differences in galaxy parameters estimated using different combinations of models and assumptions, and explore the dependence of the rest-UV portion of model spectra on stellar metallicity and population age.</p

Dust Attenuation, Star Formation, and Metallicity in z ~ 2-3 Galaxies from KBSS-MOSFIRE

We present a detailed analysis of 317 2.0 ≤ z ≤ 2.7 star-forming galaxies from the Keck Baryonic Structure Survey. Using complementary spectroscopic observations with Keck/LRIS and Keck/MOSFIRE, as well as spectral energy distribution (SED) fits to broadband photometry, we examine the joint rest-UV and rest-optical properties of the same galaxies, including stellar and nebular dust attenuation, metallicity, and star formation rate (SFR). The inferred parameters of the stellar population (reddening, age, SFR, and stellar mass) are strongly dependent on the details of the assumed stellar population model and the shape of the attenuation curve. Nebular reddening is generally larger than continuum reddening, but with large scatter. Compared to local galaxies, high-redshift galaxies have lower gas-phase metallicities (and/or higher nebular excitation) at fixed nebular reddening, and higher nebular reddening at fixed stellar mass, consistent with gas fractions that increase with redshift. We find that continuum reddening is correlated with 12 + log(O/H)_(O3N2) at 3.0σ significance, whereas nebular reddening is correlated with only 1.1σ significance. This may reflect the dependence of both continuum reddening and O3N2 on the shape of the ionizing radiation field produced by the massive stars. Finally, we show that Hα-based and SED-based estimates of SFR exhibit significant scatter relative to one another, and on average agree only for particular combinations of spectral synthesis models and attenuation curves. We find that the SMC extinction curve predicts consistent SFRs if we assume the subsolar (0.14 Z⊙) binary star models that are favored for high-redshift galaxies

Predicting Lyα Emission from Galaxies via Empirical Markers of Production and Escape in the KBSS

Lyα emission is widely used to detect and confirm high-redshift galaxies and characterize the evolution of the intergalactic medium (IGM). However, many galaxies do not display Lyα emission in typical spectroscopic observations, and intrinsic Lyα emitters represent a potentially biased set of high-redshift galaxies. In this work, we analyze a set of 703 galaxies at 2 ≾ z ≾ 3 with both Lyα spectroscopy and measurements of other rest-frame ultraviolet and optical properties in order to develop an empirical model for Lyα emission from galaxies and understand how the probability of Lyα emission depends on other observables. We consider several empirical proxies for the efficiency of Lyα photon production, as well as the subsequent escape of these photons through their local interstellar medium. We find that the equivalent width of metal-line absorption and the O3 ratio of rest-frame optical nebular lines are advantageous empirical proxies for Lyα escape and production, respectively. We develop a new quantity, X_(LIS)^(O3), that combines these two properties into a single predictor of net Lyα emission, which we find describes ~90% of the observed variance in Lyα equivalent width when accounting for our observational uncertainties. We also construct conditional probability distributions demonstrating that galaxy selection based on measurements of galaxy properties yield samples of galaxies with widely varying probabilities of net Lyα emission. The application of the empirical models and probability distributions described here may be used to infer the selection biases of current galaxy surveys and evaluate the significance of high-redshift Lyα (non)detections in studies of reionization and the IGM

Hα Imaging of Nearby Seyfert Host Galaxies

We used narrowband (Δλ = 70 Å) interference filters with the CCD imaging camera on the Nickel 1.0 m telescope at Lick Observatory to observe 31 nearby (z 67%) their H ii region emission. Only the most luminous AGNs (log(L_(Hα) /erg s^(−1)) > 41.5) would still be identified as such at z ~ 0.3

Predicting Lyα Emission from Galaxies via Empirical Markers of Production and Escape in the KBSS

Lyα emission is widely used to detect and confirm high-redshift galaxies and characterize the evolution of the intergalactic medium (IGM). However, many galaxies do not display Lyα emission in typical spectroscopic observations, and intrinsic Lyα emitters represent a potentially biased set of high-redshift galaxies. In this work, we analyze a set of 703 galaxies at 2 ≾ z ≾ 3 with both Lyα spectroscopy and measurements of other rest-frame ultraviolet and optical properties in order to develop an empirical model for Lyα emission from galaxies and understand how the probability of Lyα emission depends on other observables. We consider several empirical proxies for the efficiency of Lyα photon production, as well as the subsequent escape of these photons through their local interstellar medium. We find that the equivalent width of metal-line absorption and the O3 ratio of rest-frame optical nebular lines are advantageous empirical proxies for Lyα escape and production, respectively. We develop a new quantity, X_(LIS)^(O3), that combines these two properties into a single predictor of net Lyα emission, which we find describes ~90% of the observed variance in Lyα equivalent width when accounting for our observational uncertainties. We also construct conditional probability distributions demonstrating that galaxy selection based on measurements of galaxy properties yield samples of galaxies with widely varying probabilities of net Lyα emission. The application of the empirical models and probability distributions described here may be used to infer the selection biases of current galaxy surveys and evaluate the significance of high-redshift Lyα (non)detections in studies of reionization and the IGM

The Keck Baryonic Structure Survey: using foreground/background galaxy pairs to trace the structure and kinematics of circumgalactic neutral hydrogen at z ∼ 2

We present new measurements of the spatial distribution and kinematics of neutral hydrogen in the circumgalactic and intergalactic medium surrounding star-forming galaxies at z ∼ 2. Using the spectra of ≃3000 galaxies with redshifts 〈z〉 = 2.3 ± 0.4 from the Keck Baryonic Structure Survey, we assemble a sample of more than 200 000 distinct foreground-background pairs with projected angular separations of 3–500 arcsec and spectroscopic redshifts, with 〈z_(fg)〉 = 2.23 and 〈zbg〉 = 2.57 (foreground, background redshifts, respectively.) The ensemble of sightlines and foreground galaxies is used to construct a 2D map of the mean excess HI Lyα optical depth relative to the intergalactic mean as a function of projected galactocentric distance (20 ≲ D_(tran)/pkpc ≲ 4000) and line-of-sight velocity. We obtain accurate galaxy systemic redshifts, providing significant information on the line-of-sight kinematics of HI gas as a function of projected distance D_(tran). We compare the map with cosmological zoom-in simulation, finding qualitative agreement between them. A simple two-component (accretion, outflow) analytical model generally reproduces the observed line-of-sight kinematics and projected spatial distribution of HI. The best-fitting model suggests that galaxy-scale outflows with initial velocity v_(out) ≃ 600 km s⁻¹ dominate the kinematics of circumgalactic HI out to D_(tran) ≃ 50 kpc, while HI at D_(tran) ≳ 100 kpc is dominated by infall with characteristic v_(in) ≲ circular velocity. Over the impact parameter range 80 ≲ D_(tran)/pkpc ≲ 200, the HI line-of-sight velocity range reaches a minimum, with a corresponding flattening in the rest-frame Lyα equivalent width. These observations can be naturally explained as the transition between outflow-dominated and accretion-dominated flows. Beyond D_(tran) ≃ 300 pkpc (∼1 cMpc), the line-of-sight kinematics are dominated by Hubble expansion