Search

We present a rest-frame optical, spatially resolved analysis of more than 100 $\mathrm{H\alpha}$ emitters (HAEs) at $z\sim2.2$ in the ZFOURGE-CDFS field using NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES). The ultra-deep, high-resolution data gives us maps of the resolved emission line regions of HAEs with stellar mass ranging from $10^{8}\,M_{\odot}$ to $10^{10}\,M_{\odot}$. An [OIII] emission-line map of each HAE is created from the flux excess in the F150W filter, leading to the discovery of a population of kiloparsec-scale compact emission line regions (``Green Seeds") with high equivalent widths ($\mathrm{EW}$). We obtain a sample of 128 Green Seeds from 68 HAEs with rest-frame $\mathrm{EW_{[OIII]}}>200\r{A}$. Moreover, 17 of them have extremely large $\mathrm{EW_{[OIII]}}>1000\r{A}$, suggesting the possible Lyman continuum (LyC) leakage from these emission line regions. Embedded within the host galaxy, many Green Seeds correspond to UV star-forming clumps and H{\sc ii} regions, indicating elevated starburst activity in them, with specific star formation rates (sSFR) several times higher than that of the host galaxy. Based on theoretical frameworks, Green Seeds are expected to be formed through gravitational disk instability and/or galaxy mergers. Considering the stellar masses of Green Seeds, we speculate that high-mass Green Seeds may migrate toward the galactic center to build the central bulge, while low-mass Green Seeds are easily disrupted and short-lived. Besides, we propose that some Green Seeds could be the progenitors of globular clusters or ultracompact dwarf galaxies observed in the local universe., Comment: 29 pages, 18 figures, Submitted to ApJ

Dual active galactic nuclei (AGN) offer a unique opportunity to probe the relationship between super massive black holes (SMBH) and their host galaxies as well as the role of major mergers in triggering AGN activity. The confirmed dual AGN Mrk 266 has been studied extensively with multi-wavelength imaging. Now, high spatial resolution IFU spectroscopy of Mrk 266 provides an opportunity to probe the kinematics of both the merger event and AGN feedback. We present for the first time high spatial resolution kinematic maps for both nuclei of Mrk 266 obtained with the Keck OSIRIS IFU spectrograph, utilizing adaptive optics to achieve a resolution of 0.31" and 0.20" for the NE and SW nuclei, respectively. Using the M-sigma relation for mergers, we infer a SMBH mass of approximately 7e7 solar masses for the southwestern nucleus. Additionally, we report that the molecular gas kinematics of the southwestern nucleus are dominated by rotation rather than large-scale chaotic motions. The southwest nucleus also contains both a circumnuclear ring of star formation from which an inflow of molecular gas is likely fueling the AGN and a compact, AGN-dominated outflow of highly ionized gas with a timescale of approximately 2 Myr, significantly shorter than the timescale of the merger. The northeastern nucleus, on the other hand, exhibits complex kinematics related to the merger, including molecular gas that appears to have decoupled from the rotation of the stars. Our results suggest that while the AGN activity in Mrk 266 was likely triggered during the merger, AGN feeding is currently the result of processes internal to each host galaxy, thus resulting in a strong asymmetry between the two nuclei., Comment: 18 pages, 18 figures, 3 tables. Accepted for publication in MNRAS

We present the results of a James Webb Space Telescope (JWST) NIRCam and NIRSpec investigation into the young massive star cluster (YMC) population of NGC 3256, the most cluster-rich luminous infrared galaxy (LIRG) in the Great Observatories All Sky LIRG Survey. We detect 3061 compact YMC candidates with a $S/N \geq 3$ at F150W, F200W, and F335M. Based on yggdrasil stellar population models, we identify 116/3061 sources with F150W - F200W $> 0.47$ and F200W - F355M $> -1.37$ colors suggesting they are young (t $\leq 5$ Myr), dusty ($A_{V} = 5 - 15$), and massive ($M_{\odot} > 10^{5}$). This increases the sample of dust-enshrouded YMCs detected in this system by an order of magnitude relative to previous HST studies. With NIRSpec IFU pointings centered on the northern and southern nucleus, we extract the Pa$\alpha$ and 3.3$\mu$m PAH equivalent widths for 8 bright and isolated YMCs. Variations in both the F200W - F335M color and 3.3$\mu$m PAH emission with the Pa$\alpha$ line strength suggest a rapid dust clearing ($< 3 - 4$ Myr) for the emerging YMCs in the nuclei of NGC 3256. Finally, with both the age and dust emission accurately measured we use yggdrasil to derive the color excess (E(B - V)) for all 8 YMCs. We demonstrate that YMCs with strong 3.3$\mu$m PAH emission (F200W - F335M $> 0$) correspond to sources with E(B - V) $> 3$, which are typically missed in UV-optical studies. This underscores the importance of deep near-infrared imaging for finding and characterizing these very young and dust-embedded sources., Comment: 18 pages, 7 figures, 1 table; Accepted for publication in ApJL

The radial gradient of gas-phase metallicity is a powerful probe of the chemical and structural evolution of star-forming galaxies, closely tied to disk formation and gas kinematics in the early universe. We present spatially resolved chemical and dynamical properties for a sample of 26 galaxies at $0.5 \lesssim z \lesssim 1.7$ from the MSA-3D survey. These innovative observations provide 3D spectroscopy of galaxies at a spatial resolution approaching JWST's diffraction limit and a high spectral resolution of $R\simeq2700$. The metallicity gradients measured in our galaxy sample range from $-$0.05 to 0.02 dex~kpc$^{-1}$. Most galaxies exhibit negative or flat radial gradients, indicating lower metallicity in the outskirts or uniform metallicity throughout the entire galaxy. We confirm a tight relationship between stellar mass and metallicity gradient at $z\sim1$ with small intrinsic scatter of 0.02 dex~kpc$^{-1}$. Our results indicate that metallicity gradients become increasingly negative as stellar mass increases, likely because the more massive galaxies tend to be more "disky". This relationship is consistent with the predictions from cosmological hydrodynamic zoom-in simulations with strong stellar feedback. This work presents the effort to harness the multiplexing capability of JWST NIRSpec/MSA in slit-stepping mode to map the chemical and kinematic profiles of high-redshift galaxies in large samples and at high spatial and spectral resolution., Comment: 23 pages, 6 figures, 1 table; submitted to ApJL

Polycyclic aromatic hydrocarbon (PAH) dust emission has been proposed as an effective extinction-independent star formation rate (SFR) indicator in the mid-infrared (MIR), but this may depend on conditions in the interstellar medium. The coverage of the AKARI/Infrared Camera (IRC) allows us to study the effects of metallicity, starburst intensity, and active galactic nuclei on PAH emission in galaxies with $f_{\nu}(L18W)\lesssim 19$ AB mag. Observations include follow-up, rest-frame optical spectra of 443 galaxies within the AKARI North Ecliptic Pole survey that have IRC detections from 7-24 $\mu$m. We use optical emission line diagnostics to infer SFR based on H$\alpha$ and [O II]$\lambda\lambda 3726,3729$ emission line luminosities. The PAH 6.2 $\mu$m and PAH 7.7 $\mu$m luminosities ($L(PAH\ 6.2\ \mu m)$ and $L(PAH\ 7.7\ \mu m)$, respectively) derived using multi-wavelength model fits are consistent with those derived from slitless spectroscopy within 0.2 dex. $L(PAH\ 6.2\ \mu m)$ and $L(PAH\ 7.7\ \mu m)$ correlate linearly with the 24 $\mu$m-dust corrected H$\alpha$ luminosity only for normal, star-forming ``main-sequence" galaxies. Assuming multi-linear correlations, we quantify the additional dependencies on metallicity and starburst intensity, which we use to correct our PAH SFR calibrations at $0

Integral field spectroscopy (IFS) is a powerful tool for understanding the formation of galaxies across cosmic history. We present the observing strategy and first results of MSA-3D, a novel JWST program using multi-object spectroscopy in a slit-stepping strategy to produce IFS data cubes. The program observed 43 normal star-forming galaxies at redshifts $0.5 \lesssim z \lesssim 1.5$, corresponding to the epoch when spiral thin-disk galaxies of the modern Hubble sequence are thought to emerge, obtaining kpc-scale maps of rest-frame optical nebular emission lines with spectral resolution $R\simeq2700$. Here we describe the multiplexed slit-stepping method which is $>15$ times more efficient than the NIRSpec IFS mode for our program. As an example of the data quality, we present a case study of an individual galaxy at $z=1.104$ (stellar mass $M_{*} = 10^{10.3}~M_{\odot}$, star formation rate~$=3~M_{\odot}$ yr$^{-1}$) with prominent face-on spiral structure. We show that the galaxy exhibits a rotationally supported disk with moderate velocity dispersion ($\sigma = 36^{+5}_{-4}$~\kms), a negative radial metallicity gradient ($-0.020\pm0.002$~dex\,kpc$^{-1}$), a dust attenuation gradient, and an exponential star formation rate density profile which closely matches the stellar continuum. These properties are characteristic of local spirals, indicating that mature galaxies are in place at $z\sim1$. We also describe the customized data reduction and original cube-building software pipelines which we have developed to exploit the powerful slit-stepping technique. Our results demonstrate the ability of JWST slit-stepping to study galaxy populations at intermediate to high redshifts, with data quality similar to current surveys of the $z\sim0.1$ universe., Comment: 24 pages, 12 figures, 1 table; submitted to ApJ, comments welcome. Our custom designed data reduction pipeline (MSA3D) and example processed data-cube will be publicly released before the JWST Cycle 4 deadline. MSA3D package on GitHub: https://github.com/barisiciv/msa3d.git

We present multiwavelength observations of the Swift short $\gamma$-ray burst GRB 231117A, localized to an underlying galaxy at redshift $z = 0.257$ at a small projected offset ($\sim 2~$kpc). We uncover long-lived X-ray (Chandra) and radio/millimeter (VLA, MeerKAT, and ALMA) afterglow emission, detected to $\sim 37~$days and $\sim 20~$days (rest frame), respectively. We measure a wide jet ($\sim 10.4^\circ$) and relatively high circumburst density ($\sim 0.07~{\rm cm}^{-3}$) compared to the short GRB population. Our data cannot be easily fit with a standard forward shock model, but they are generally well fit with the incorporation of a refreshed forward shock and a reverse shock at $< 1~$day. We incorporate GRB 231117A into a larger sample of 132 X-ray detected events, 71 of which were radio-observed (17 cm-band detections), for a systematic study of the distributions of redshifts, jet and afterglow properties, galactocentric offsets, and local environments of events with and without detected radio afterglows. Compared to the entire short GRB population, the majority of radio-detected GRBs are at relatively low redshifts ($z < 0.6$) and have high circumburst densities ($> 10^{-2}~{\rm cm}^{-3}$), consistent with their smaller ($< 8~$kpc) projected galactocentric offsets. We additionally find that 70% of short GRBs with opening angle measurements were radio-detected, indicating the importance of radio afterglows in jet measurements, especially in the cases of wide ($> 10^\circ$) jets where observational evidence of collimation may only be detectable at radio wavelengths. Owing to improved observing strategies and the emergence of sensitive radio facilities, the number of radio-detected short GRBs has quadrupled in the past decade., Comment: 30 pages, 11 figures, submitted to ApJ

We present James Webb Space Telescope (JWST) Integral Field Spectrograph observations of NGC 3256, a local infrared-luminous late-stage merging system with two nuclei about 1 kpc apart, both of which have evidence of cold molecular outflows. Using JWST NIRSpec and MIRI datasets, we investigate this morphologically complex system on spatial scales of $<$100 pc, where we focus on the warm molecular H$_2$ gas surrounding the nuclei. We detect collimated outflowing warm H$_2$ gas originating from the southern nucleus, though we do not find significant outflowing warm H$_2$ gas surrounding the northern nucleus. Within the observed region, the maximum intrinsic velocities of the outflow reach up to $\sim$1,000 km s$^{-1}$, and extend out to a distance of 0.7 kpc. Based on H$_2$ S(7)/S(1) line ratios, we find a larger fraction of warmer gas near the S nucleus, which decreases with increasing distance from the nucleus, signifying the S nucleus as a primary source of H$_2$ heating. The gas mass of the warm H$_2$ outflow component is estimated to be $M\rm{_{warm,out}}$ = 8.9$\times$10$^5\;M_{\odot}$, as much as 4$\%$ of the cold H$_2$ mass as estimated using ALMA CO data. The outflow time scale is about $7\times10^5$ yr, resulting in a mass outflow rate of $\dot{M}\rm{_{warm,out}}$ = 1.3 M$_{\odot}$ yr$^{-1}$ and kinetic power of $P\rm{_{warm,out}}\;\sim\;2\times10^{41}$ erg s$^{-1}$. Lastly, the regions where the outflowing gas reside show high [FeII]/Pa$\beta$ and H$_2$/Br$\gamma$ line ratios, indicating enhanced mechanical heating caused by the outflows. At the same time, the 3.3 $\mu$m and 6.2 $\mu$m Polycyclic Aromatic Hydrocarbon fluxes in these regions are not significantly suppressed compared to those outside the outflows, suggesting the outflows have no clear negative feedback effect on the local star formation., Comment: 16 pages, 8 figures. Submitted to ApJ

We spectroscopically confirm the $M_{\rm UV} = -20.5$ mag galaxy GHZ2/GLASS-z12 to be at redshift $z=12.34$. The source was selected via NIRCam photometry in GLASS-JWST ERS data, providing the first evidence of a surprising abundance of bright galaxies at $z \gtrsim 10$. The NIRSpec PRISM spectrum shows detections of N IV, C IV, He II, O III, C III, O II, and Ne III lines, and the first detection at high-redshift of the O III Bowen fluorescence line at 3133 {\AA} rest-frame. The prominent C IV line with rest-frame equivalent width (EW) $\approx 46$ {\AA} puts GHZ2 in the category of extreme C IV emitters. GHZ2 displays UV lines with EWs that are only found in active galactic nuclei (AGNs) or composite objects at low/intermediate redshifts. The UV line-intensity ratios are compatible both with AGNs and star formation in a low-metallicity environment, with the low limit on the [Ne IV]/[N IV] ratio favoring a stellar origin of the ionizing photons. We discuss a possible scenario in which the high ionizing output is due to low metallicity stars forming in a dense environment. We estimate a metallicity $\lesssim 0.1 Z/{\rm Z}_{\odot}$, a high ionization parameter logU $> -2$, a N/O abundance 4--5 times the solar value, and a subsolar C/O ratio similar to the recently discovered class of nitrogen-enhanced objects. Considering its abundance patterns and the high stellar mass density ($10^4$~M$_{\odot}$~pc$^{-2}$), GHZ2 is an ideal formation site for the progenitors of today's globular clusters. The remarkable brightness of GHZ2 makes it a ``Rosetta stone'' for understanding the physics of galaxy formation within just 360 Myr after the Big Bang., Comment: Accepted for publication in The Astrophysical Journal. 20 pages, 7 figures, 2 tables

Using integrated spectra for two gravitationally lensed galaxies from the JWST TEMPLATES Early Release Science program, we analyze faint auroral lines, which provide direct measurements of the gas-phase chemical abundance. For the brighter galaxy, SGAS1723$+$34 ($z = 1.3293$), we detect the [OIII]$\lambda4363$, [SIII]$\lambda6312$, and [OII]$\lambda\lambda$7320,7330 auroral emission lines, and set an upper limit for the [NII]$\lambda5755$ line. For the second galaxy, SGAS1226$+$21 ($z = 2.925$), we do not detect any auroral lines, and report upper limits. With these measurements and upper limits, we constrain the electron temperatures in different ionization zones within both of these galaxies. For SGAS1723$+$34, where auroral lines are detected, we calculate direct oxygen and nitrogen abundances, finding an N/O ratio consistent with observations of nearby ($z\sim 0$) galaxies. These observations highlight the potent combination of JWST and gravitational lensing to measure faint emission lines in individual distant galaxies and to directly study the chemical abundance patterns in those galaxies., Comment: Submitted to the Astrophysical Journal's Focus Issue on the TEMPLATES JWST Early Release Science Program. 15 pages, 6 figures. Comments welcome

We measure the bolometric luminosity of a complete and unbiased 12 micron-selected sample of active galactic nuclei (AGN) in the local Universe. For each galaxy we used a 10-band radio-to-X-ray Spectral Energy Distribution (SED) to isolate the genuine AGN continuum in each band, including sub-arcsecond measurements where available, and correcting those contaminated by the host galaxy. We derive the median SED of Seyfert type 1 AGN, Seyferts with hidden broad-lines (HBL), Seyferts of type 2, and LINER nuclei in our sample. The median Seyfert 1 SED shows the characteristic blue bump feature in the UV, but nevertheless the largest contribution to the bolometric luminosity comes from the IR and X-ray continua. The median SEDs of both HBL and type 2 AGN are affected by starlight contamination in the optical/UV. The median SED of HBL AGN is consistent with that of Seyfert 1's, when an extinction of Av = 1.2 mag is applied. The comprehensive SEDs allowed us to measure accurate bolometric luminosities and derive robust bolometric corrections for the different tracers. The 12 micron and the K-band nuclear luminosities have good linear correlations with the bolometric luminosity, similar to those in the X-rays. We derive bolometric corrections for either continuum bands (K-band, 12 micron, 2-10 keV and 14-195 keV) and narrow emission lines (mid-IR high ionization lines of [OIV] and [NeV] and optical [OIII]5007A) as well as for combinations of IR continuum and line emission. A combination of continuum plus line emission accurately predicts the bolometric luminosity up to quasar luminosities., Comment: Accepted for publication in the Astrophysical Journal on December 20, 2023

We present a measurement of the mass-metallicity relation (MZR) at cosmic noon, using the JWST near-infrared wide-field slitless spectroscopy obtained by the GLASS-JWST Early Release Science program. By combining the power of JWST and the lensing magnification by the foreground cluster A2744, we extend the measurements of the MZR to the dwarf mass regime at high redshifts. A sample of 50 galaxies with several emission lines is identified across two wide redshift ranges of $z=1.8-2.3$ and $2.6-3.4$ in the stellar mass range of $\log{(M_*/M_\odot)}\in [6.9, 10.0]$. The observed slope of MZR is $0.223 \pm 0.017$ and $0.294 \pm 0.010$ at these two redshift ranges, respectively, consistent with the slopes measured in field galaxies with higher masses. In addition, we assess the impact of the morphological broadening on emission line measurement by comparing two methods of using 2D forward modeling and line profile fitting to 1D extracted spectra. We show that ignoring the morphological broadening effect when deriving line fluxes from grism spectra results in a systematic reduction of flux by $\sim30\%$ on average. This discrepancy appears to affect all the lines and thus does not lead to significant changes in flux ratio and metallicity measurements. This assessment of the morphological broadening effect using JWST data presents, for the first time, an important guideline for future work deriving galaxy line fluxes from wide-field slitless spectroscopy, such as Euclid, Roman, and the Chinese Space Station Telescope., Comment: 19 pages, 6 figures, accepted for publication in ApJL

Observed scatter in the Lyman-alpha opacity of quasar sightlines at $z<6$ has motivated measurements of the correlation between Ly$\alpha$ opacity and galaxy density, as models that predict this scatter make strong and sometimes opposite predictions for how they should be related. Our previous work associated two highly opaque Ly$\alpha$ troughs at $z\sim5.7$ with a deficit of Lyman-$\alpha$ emitting galaxies (LAEs). In this work, we survey two of the most highly transmissive lines of sight at this redshift, towards the $z=6.02$ quasar SDSS J1306+0356 and the $z=6.17$ quasar PSO J359-06. We find that both fields are underdense in LAEs within 10 $h^{-1}$ Mpc of the quasar sightline, somewhat less extensive than underdensities associated with Ly$\alpha$ troughs. We combine our observations with three additional fields from the literature, and find that while fields with extreme opacities are generally underdense, moderate opacities span a wider density range. The results at high opacities are consistent with models that invoke UV background fluctuations and/or late reionization to explain the observed scatter in IGM Ly$\alpha$ opacities. There is tension at low opacities, however, as the models tend to associate lower IGM Ly$\alpha$ opacities with higher densities. Although the number of fields surveyed is still small, the low-opacity results may support a scenario in which the ionizing background in low-density regions increases more rapidly than some models suggest after becoming ionized. Elevated gas temperatures from recent reionization may also be making these regions more transparent., Comment: 20 pages, 17 figures. Accepted to ApJ

We present new JWST-NIRSpec IFS data for the luminous infrared galaxy NGC7469: a nearby (70.6Mpc) active galaxy with a Sy 1.5 nucleus that drives a highly ionized gas outflow and a prominent nuclear star-forming ring. Using the superb sensitivity and high spatial resolution of the JWST instrument NIRSpec-IFS, we investigate the role of the Seyfert nucleus in the excitation and dynamics of the circumnuclear gas. Our analysis focuses on the [Fe ii], H2, and hydrogen recombination lines that trace the radiation/shocked-excited molecular and ionized ISM around the AGN. We investigate the gas excitation through H2/Br{\gamma} and [Fe ii]/Pa\b{eta} emission line ratios and find that photoionization by the AGN dominates within the central 300 pc of the galaxy and together with a small region show ing signatures of shock-heated gas; these shock-heated regions are likely associated with a compact radio jet. In addition, the velocity field and velocity dispersion maps reveal complex gas kinematics. Rotation is the dominant feature, but we also identify non-circular motions consistent with gas inflows as traced by the velocity residuals and the spiral pattern in the Pa{\alpha} velocity dispersion map. The inflow is consistent with the mass outflow rate and two orders of magnitude higher than the AGN accretion rate. The compact nuclear radio jet has enough power to drive the highly ionized outflow. This scenario suggests that the inflow and outflow are in a self-regulating feeding-feedback process, with a contribution from the radio jet helping to drive the outflow., Comment: 15 pages, 4 figures, 3 tables, accepted for publication in ApJ

We present James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec) integral-field spectroscopy of the nearby luminous infrared galaxy, NGC 7469. We take advantage of the high spatial/spectral resolution and wavelength coverage of JWST /NIRSpec to study the 3.3 um neutral polycyclic aromatic hydrocarbon (PAH) grain emission on ~60 pc scales. We find a clear change in the average grain properties between the star-forming ring and the central AGN. Regions in the vicinity of the AGN, with [NeIII]/[NeII]>0.25, tend to have larger grain sizes and lower aliphatic-to-aromatic (3.4/3.3) ratios indicating that smaller grains are preferentially removed by photo-destruction in the vicinity of the AGN. We find an overall suppression of the total PAH emission relative to the ionized gas in the central 1 kpc region of the AGN in NGC 7469 compared to what has been observed with Spitzer on 3 kpc scales. However, the fractional 3.3 um to total PAH power is enhanced in the starburst ring, possibly due to a variety of physical effects on sub-kpc scales, including recurrent fluorescence of small grains or multiple photon absorption by large grains. Finally, the IFU data show that while the 3.3 um PAH-derived star formation rate (SFR) in the ring is 8% higher than that inferred from the [NeII] and [NeIII] emission lines, the integrated SFR derived from the 3.3 um feature would be underestimated by a factor of two due to the deficit of PAHs around the AGN, as might occur if a composite system like NGC 7469 were to be observed at high-redshift., Comment: 14 pages, 5 figures, 2 tables, Submitted to ApJL

We present the first spatially resolved maps of gas-phase metallicity for two dust-obscured star-forming galaxies (DSFGs) at $z\sim$ 4, from the JWST TEMPLATES Early Release Science program, derived from NIRSpec integral field unit spectroscopy of the H$\alpha$ and [NII] emission lines. Empirical optical line calibrations are used to determine that the sources are globally enriched to near-solar levels. While one source shows elevated [NII]/H$\alpha$ ratios and broad H$\alpha$ emission consistent with the presence of an AGN in a $\gtrsim$1kpc region, we argue that both systems have already undergone significant metal enrichment as a result of their extremely high star formation rates. Utilizing ALMA rest-frame 380$\mu$m continuum and [CI]($^3$P$_2$-$^3$P$_1$) line maps we compare the spatial variation of the metallicity and gas-to-dust ratio in the two galaxies, finding the two properties to be anticorrelated on highly resolved spatial scales, consistent with various literature studies of $z\sim$ 0 galaxies. The data are indicative of the enormous potential of JWST to probe the enrichment of the interstellar medium on $\sim$kpc scales in extremely dust-obscured systems at $z\sim$ 4 and beyond., Comment: 14 pages, 6 figures, accepted for publication in ApJ

The broad line region (BLR) size-luminosity relation has paramount importance for estimating the mass of black holes in active galactic nuclei (AGNs). Traditionally, the size of the H$\beta$ BLR is often estimated from the optical continuum luminosity at 5100\angstrom{} , while the size of the H$\alpha$ BLR and its correlation with the luminosity is much less constrained. As a part of the Seoul National University AGN Monitoring Project (SAMP) which provides six-year photometric and spectroscopic monitoring data, we present our measurements of the H$\alpha$ lags of 6 high-luminosity AGNs. Combined with the measurements for 42 AGNs from the literature, we derive the size-luminosity relations of H$\alpha$ BLR against broad H$\alpha$ and 5100\angstrom{} continuum luminosities. We find the slope of the relations to be $0.61\pm0.04$ and $0.59\pm0.04$, respectively, which are consistent with the \hb{} size-luminosity relation. Moreover, we find a linear relation between the 5100\angstrom{} continuum luminosity and the broad H$\alpha$ luminosity across 7 orders of magnitude. Using these results, we propose a new virial mass estimator based on the H$\alpha$ broad emission line, finding that the previous mass estimates based on the scaling relations in the literature are overestimated by up to 0.7 dex at masses lower than $10^7$~M$_{\odot}$., Comment: Accepted for publication in ApJ (Jun. 25th, 2023). 21 pages, 12 figures

Dust grains absorb half of the radiation emitted by stars throughout the history of the universe, re-emitting this energy at infrared wavelengths. Polycyclic aromatic hydrocarbons (PAHs) are large organic molecules that trace millimeter-size dust grains and regulate the cooling of the interstellar gas within galaxies. Observations of PAH features in very distant galaxies have been difficult due to the limited sensitivity and wavelength coverage of previous infrared telescopes. Here we present JWST observations that detect the 3.3um PAH feature in a galaxy observed less than 1.5 billion years after the Big Bang. The high equivalent width of the PAH feature indicates that star formation, rather than black hole accretion, dominates the infrared emission throughout the galaxy. The light from PAH molecules, large dust grains, and stars and hot dust are spatially distinct from one another, leading to order-of-magnitude variations in the PAH equivalent width and the ratio of PAH to total infrared luminosity across the galaxy. The spatial variations we observe suggest either a physical offset between the PAHs and large dust grains or wide variations in the local ultraviolet radiation field. Our observations demonstrate that differences in the emission from PAH molecules and large dust grains are a complex result of localized processes within early galaxies., Comment: Published in Nature 5 June 2023 at https://www.nature.com/articles/s41586-023-05998-6. MIRI MRS reduction notebook is available at https://github.com/jwst-templates

In late 2014, four images of Supernova (SN) "Refsdal," the first known example of a strongly lensed SN with multiple resolved images, were detected in the MACS J1149 galaxy-cluster field. Following the images' discovery, the SN was predicted to reappear within hundreds of days at a new position ~8 arcseconds away in the field. The observed reappearance in late 2015 makes it possible to carry out Refsdal's (1964) original proposal to use a multiply imaged SN to measure the Hubble constant H0, since the time delay between appearances should vary inversely with H0. Moreover, the position, brightness, and timing of the reappearance enable a novel test of the blind predictions of galaxy-cluster models, which are typically constrained only by the positions of multiply imaged galaxies. We have developed a new photometry pipeline that uses DOLPHOT to measure the fluxes of the five images of SN Refsdal from difference images. We apply four separate techniques to perform a blind measurement of the relative time delays and magnification ratios (mu_i/mu_1) between the last image SX and the earlier images S1-S4. We measure the relative time delay of SX-S1 to be 376.0+5.6-5.5 days and the relative magnification to be 0.30+0.05-0.03. This corresponds to a 1.5% precision on the time delay and 17% precision for the magnification ratios, and includes uncertainties due to millilensing and microlensing. In an accompanying paper, we place initial and blind constraints on the value of the Hubble constant., Comment: Published in ApJ. Companion paper presenting H0 constraints published in Science (DOI: 10.1126/science.abh1322)

We combine our dynamical modeling black hole mass measurements from the Lick AGN Monitoring Project 2016 sample with measured cross-correlation time lags and line widths to recover individual scale factors, f, used in traditional reverberation mapping analyses. We extend our sample by including prior results from Code for AGN Reverberation and Modeling of Emission Lines (caramel) studies that have utilized our methods. Aiming to improve the precision of black hole mass estimates, as well as uncover any regularities in the behavior of the broad-line region (BLR), we search for correlations between f and other AGN/BLR parameters. We find (i) evidence for a correlation between the virial coefficient log10(fmean,{\sigma}) and black hole mass, (ii) marginal evidence for a similar correlation between log10(frms,{\sigma}) and black hole mass, (iii) marginal evidence for an anti-correlation of BLR disk thickness with log10(fmean,FWHM)and log10(frms,FWHM), and (iv) marginal evidence for an anti-correlation of inclination angle with log10(fmean,FWHM), log10(frms,{\sigma}), and log10(fmean,{\sigma}). Lastly, we find marginal evidence for a correlation between line-profile shape, when using the root-meansquare spectrum, log10(FWHM/{\sigma})rms, and the virial coefficient, log10(frms,{\sigma}), and investigate how BLR properties might be related to line-profile shape using caramel models., Comment: 17 pages, 10 figures

We combine JWST/NIRCam imaging and MUSE data to characterize the properties of galaxies in different environmental conditions in the cluster Abell2744 ($z=0.3064$) and in its immediate surroundings. We investigate how galaxy colors, morphology and star forming fractions depend on wavelength and on different parameterizations of environment. Our most striking result is the discovery of a ``red-excess'' population in F200W$-$F444W colors both in the cluster regions and the field. These galaxies have normal F115W$-$F150W colors, but are up to 0.8 mag redder than red sequence galaxies in F200W$-$F444W. They also have rather blue rest frame B$-$V colors. {Galaxies in the field and at the cluster virial radius are overall characterized by redder colors, but galaxies with the largest color deviations are found in the field and in the cluster core. Several results} suggest that mechanisms taking place in these regions might be more effective in producing these colors. Looking at their morphology, many cluster galaxies show signatures consistent with ram pressure stripping, while field galaxies have features resembling interactions and mergers. Our hypothesis is that these galaxies are characterized by dust enshrouded star formation: a JWST/NIRSpec spectrum for one of the galaxies is dominated by a strong PAH at 3.3$\mu m$, suggestive of dust obscured star formation. Larger spectroscopic samples are needed to understand if the color excess is due exclusively to dust-obscured star formation, and the role of environment in triggering it., Comment: ApJL in press

External accretion events such as a galaxy merger or the accretion of gas from the immediate environment of a galaxy, can create a large misalignment between the gas and the stellar kinematics. Numerical simulations have suggested that misaligned structures may promote the inflow of gas to the nucleus of the galaxy and the accretion of gas by the central supermassive black hole. We show for the first time that galaxies with a strong misalignment between the ionised gas and stellar kinematic angles have a higher observed fraction of active black holes than galaxies with aligned rotation of gas and stars. The increase in black hole activity suggests that the process of formation and/or presence of misaligned structures is connected with the fuelling of active supermassive black holes., Comment: To be published in Nature Astronomy on 19 January 2023. Authors' version

Cosmic hydrogen reionization and cosmic production of first metals are major phase transitions of the universe occurring during the first billion years after the Big Bang, however these are still underexplored observationally. Using the JWST NIRSpec prism spectroscopy, we report the discovery of a sub-$L_\ast$ galaxy at $z_{\rm spec}=8.1623\pm0.0007$, dubbed RXJ2129-z8HeII, via the detection of a series of strong rest-frame UV/optical nebular emission lines and the clear Lyman break. RXJ2129-z8HeII shows a pronounced UV continuum with an extremely steep (i.e. blue) spectral slope of $\beta=-2.53_{-0.07}^{+0.06}$, the steepest amongst all spectroscopically confirmed galaxies at $z_{\rm spec}\gtrsim7$, in support of its very hard ionizing spectrum that could lead to a significant leakage of its ionizing flux. Therefore, RXJ2129-z8HeII is representative of the key galaxy population driving the cosmic reionization. More importantly, we detect a strong He II $\lambda$1640 emission line in its spectrum, one of the highest redshifts at which such a line is robustly detected. Its high rest-frame equivalent width (${\rm EW}=21\pm4$ Angstrom) and extreme flux ratios with respect to UV metal and Balmer lines raise the possibility that part of RXJ2129-z8HeII's stellar populations could be Pop III-like. Through careful photoionization modeling, we show that the physically calibrated phenomenological models of the ionizing spectra of Pop III stars with strong mass loss can successfully reproduce the emission line flux ratios observed in RXJ2129-z8HeII. Assuming the Eddington limit, the total mass of the Pop III stars within this system is estimated to be $7.8\pm1.4\times10^5 M_\odot$. To date, this galaxy presents the most compelling case in the early universe where trace Pop III stars might coexist with metal-enriched populations., Comment: Accepted to ApJL. 24 pages, 12 figures, and 5 tables

In the first billion years after the Big Bang, sources of ultraviolet (UV) photons are believed to have ionized intergalactic hydrogen, rendering the Universe transparent to UV radiation. Galaxies brighter than the characteristic luminosity $L^{*}$ do not provide enough ionizing photons to drive this cosmic reionization. Fainter galaxies are thought to dominate the photon budget; however they are surrounded by neutral gas that prevents the escape of the Lyman-$\alpha$ photons, which has been the dominant way to identify them so far. JD1 was previously identified as a triply-imaged galaxy with a magnification factor of 13 provided by the foreground cluster Abell 2744, and a photometric redshift of $z\sim10$. Here we report the spectroscopic confirmation of this very low luminosity ($\sim0.05 L^{*}$) galaxy at $z=9.79$, observed 480 Myr after the Big Bang, by means of the identification of the Lyman break and redward continuum, as well as multiple $\gtrsim4\sigma$ emission lines, with the Near-InfraRed Spectrograph (NIRSpec) and Near-InfraRed Camera (NIRCam) instruments. The combination of the James Webb Space Telescope (JWST) and gravitational lensing shows that this ultra-faint galaxy ($M_{\rm UV}=-17.35$) -- with a luminosity typical of the sources responsible for cosmic reionization -- has a compact ($\sim$150 pc) and complex morphology, low stellar mass (10$^{7.19}$ M$_\odot$), and subsolar ($\sim$0.6 $Z_{\odot}$) gas-phase metallicity., Comment: Matched to the published Nature version of the article. 19 pages, 4 main figures, 1 supplementary figure, 1 supplementary tables. This version includes an updated version of the NIRSpec spectrum and NIRCam photometry

We present the results of a {\it James Webb Space Telescope} NIRCam investigation into the young massive star cluster (YMC) population in the luminous infrared galaxy VV 114. We identify 374 compact YMC candidates with a $S/N \geq 3$, 5, and 5 at F150W, F200W, and F356W respectively. A direct comparison with our {\it HST} cluster catalog reveals that $\sim 20\%$ of these sources are undetected at optical wavelengths. Based on {\it yggdrasil} stellar population models, we identify 17 YMC candidates in our {\it JWST} imaging alone with F150W-F200W and F200W-F356W colors suggesting they are all very young, dusty ($A_{V} = 5 - 15$), and massive ($10^{5.8} < M_{\odot} < 10^{6.1}$). The discovery of these `hidden' sources, many of which are found in the `overlap' region between the two nuclei, quadruples the number of $t < 3$ Myr clusters, and nearly doubles the number of $t < 6$ Myr clusters detected in VV 114. Now extending the cluster age distribution ($dN/d\tau \propto \tau^{\gamma}$) to the youngest ages, we find a slope of $\gamma = -1.30 \pm 0.39$ for $10^{6} < \tau (\mathrm{yr}) < 10^{7}$, which is consistent with the previously determined value from $10^{7} < \tau (\mathrm{yr}) < 10^{8.5}$, and confirms that VV 114 has a steep age distribution slope for all massive star clusters across the entire range of cluster ages observed. Finally, the consistency between our {\it JWST}- and {\it HST}-derived age distribution slopes indicates that the balance between cluster formation and destruction has not been significantly altered in VV 114 over the last 0.5 Gyr., Comment: 13 pages, 4 figures, 1 table, published in the Astrophysical Journal

The high-ionization mid-IR lines, excited in the Narrow Line Regions (NLR) of Active Galactic Nuclei (AGN), barely affected by stellar excitation and dust extinction, trace the AGN bolometric power. We used the complete 12 micron sample of Seyfert galaxies, for which 100/116 objects have reliable 2-10keV observations. The [NeV] and [OIV] mid-IR lines linearly correlate with several AGN bolometric indicators (intrinsic 2-10keV and observed 14-195keV X-ray emission, compact nuclear 12 micron emission, [OIII] 5007A line emission), both in terms of flux and luminosity. No evidence of systematic differences in these correlations is found among the Seyfert populations, including type 1 and type 2, and Compton thick and thin AGN. Nevertheless, we find that a sequence of high-to-low Eddington ratio together with strong-to-weak line excitation (traced by the [OIV]/[Ne II] line ratio) encompasses from type 1 through type 2 AGN to Low Ionization Nuclear Emission Line Region (LINER) galaxies, showing intrinsic differences in these three AGN populations. A positive correlation between the Black Hole Accretion Rate (BHAR) and the Star Formation Rate (SFR) is found, but no correlation between the specific SFR (sSFR) and the ratio BHAR/M_(BH), simply reflecting the fact that the more massive is a galaxy, the more it is forming stars and feeding its central black hole. The JWST telescope, just beginning operations, will allow large samples of AGN to be observed in these lines in the nearby Universe (z<0.9)., Comment: To be published in The Astrophysical Journal

We present James Webb Space Telescope (JWST) Mid-InfraRed Instrument (MIRI) integral-field spectroscopy of the nearby merging, luminous infrared galaxy, NGC 7469. This galaxy hosts a Seyfert type-1.5 nucleus, a highly ionized outflow, and a bright, circumnuclear star-forming ring, making it an ideal target to study AGN feedback in the local Universe. We take advantage of the high spatial/spectral resolution of JWST/MIRI to isolate the star-forming regions surrounding the central active nucleus and study the properties of the dust and warm molecular gas on ~100 pc scales. The starburst ring exhibits prominent Polycyclic Aromatic Hydrocarbon (PAH) emission, with grain sizes and ionization states varying by only ~30%, and a total star formation rate of $\rm 10 - 30 \ M_\odot$/yr derived from fine structure and recombination emission lines. Using pure rotational lines of H2, we detect 1.2$\times$10$^{7} \rm \ M_\odot$ of warm molecular gas at a temperature higher than 200 K in the ring. All PAH bands get significantly weaker towards the central source, where larger and possibly more ionized grains dominate the emission. However, the bulk of the dust and molecular gas in the ring appears unaffected by the ionizing radiation or the outflowing wind from the AGN. These observations highlight the power of JWST to probe the inner regions of dusty, rapidly evolving galaxies for signatures of feedback and inform models that seek to explain the co-evolution of supermassive black holes and their hosts., Comment: 13 pages, 4 figures, 2 tables, Submitted to ApJL

We present James Webb Space Telescope (JWST) imaging of NGC 7469 with the Near-Infrared Camera (NIRCam) and the Mid-InfraRed Instrument (MIRI). NGC 7469 is a nearby, $z=0.01627$, luminous infrared galaxy (LIRG) that hosts both a Seyfert Type-1.5 nucleus and a circumnuclear starburst ring with a radius of $\sim$0.5 kpc. The new near-infrared (NIR) JWST imaging reveals 66 star-forming regions, 37 of which were not detected by HST observations. Twenty-eight of the 37 sources have very red NIR colors that indicate obscurations up to A$_{\rm{v}}\sim7$ and a contribution of at least 25$\%$ from hot dust emission to the 4.4$\mu$m band. Their NIR colors are also consistent with young ($<$5 Myr) stellar populations and more than half of them are coincident with the MIR emission peaks. These younger, dusty star-forming regions account for $\sim$6$\%$ and $\sim$17$\%$ of the total 1.5$\mu$m and 4.4$\mu$m luminosity of the starburst ring, respectively. Thanks to JWST, we find a significant number of young dusty sources that were previously unseen due to dust extinction. The newly identified 28 young sources are a significant increase compared to the number of HST-detected young sources (4-5). This makes the total percentage of the young population rise from $\sim$15$\%$ to 48$\%$. These results illustrate the effectiveness of JWST in identifying and characterizing previously hidden star formation in the densest star-forming environments around AGN., Comment: 4 figures, 1 table, Accepted by ApJL

The nearby, luminous infrared galaxy (LIRG) NGC 7469 hosts a Seyfert nucleus with a circumnuclear star-forming ring and is thus the ideal local laboratory for investigating the starburst--AGN connection in detail. We present integral-field observations of the central 1.3 kpc region in NGC 7469 obtained with the JWST Mid-InfraRed Instrument. Molecular and ionized gas distributions and kinematics at a resolution of {\sim}100 pc over the 4.9 - 7.6{\mu}m region are examined to study gas dynamics influenced by the central AGN. The low-ionization [Fe II] {\lambda}5.34{\mu}m and [Ar II] {\lambda}6.99{\mu}m lines are bright on the nucleus and in the starburst ring, as opposed to H2 S(5) {\lambda}6.91{\mu}m which is strongly peaked at the center and surrounding ISM. The high-ionization [Mg V] line is resolved and shows a broad, blueshifted component associated with the outflow. It has a nearly face-on geometry that is strongly peaked on the nucleus, where it reaches a maximum velocity of -650 km/s, and extends about 400 pc to the East. Regions of enhanced velocity dispersion in H2 and [Fe II] {\sim}180 pc from the AGN that also show high L(H2)/L(PAH) and L([Fe II])/L(Pf{\alpha}) ratios to the W and N of the nucleus pinpoint regions where the ionized outflow is depositing energy, via shocks, into the dense interstellar medium between the nucleus and the starburst ring. These resolved mid-infrared observations of the nuclear gas dynamics demonstrate the power of JWST and its high-sensitivity integral-field spectroscopic capability to resolve feedback processes around supermassive black holes in the dusty cores of nearby LIRGs., Comment: 14 pages, 6 figures, 1 table; accepted for publication in ApJL

James Webb Space Telescope (JWST) Mid-InfraRed Instrument (MIRI) images of the luminous infrared (IR) galaxy VV 114 are presented. This redshift ~ 0.020 merger has a western component (VV 114W) rich in optical star clusters and an eastern component (VV 114E) hosting a luminous mid-IR nucleus hidden at UV and optical wavelengths by dust lanes. With MIRI, the VV 114E nucleus resolves primarily into bright NE and SW cores separated by 630 pc. This nucleus comprises 45% of the 15um light of VV 114, with the NE and SW cores having IR luminosities, L_ IR (8-1000um) ~ 8+/-0.8x10^10 L_sun and ~ 5+/-0.5x10^10 L_sun, respectively, and IR densities, Sigma_IR >~ 2+/-0.2x10^13 L_sun / kpc^2 and >~ 7+/-0.7x10^12 L_sun / kpc^2, respectively -- in the range of Sigma_IR for the Orion star-forming core and the nuclei of Arp 220. The NE core, previously speculated to have an Active Galactic Nucleus (AGN), has starburst-like mid-IR colors. In contrast, the VV 114E SW has AGN-like colors. Approximately 40 star-forming knots with L_IR ~ 0.02-5x10^10 L_sun are identified, 25% of which have no optical counterpart. Finally, diffuse emission accounts for 40-60% of the mid-IR emission. Mostly notably, filamentary Poly-cyclic Aromatic Hydrocarbon (PAH) emission stochastically excited by UV and optical photons accounts for half of the 7.7um light of VV 114. This study illustrates the ability of JWST to detect obscured compact activity and distributed PAH emission in the most extreme starburst galaxies in the local Universe., Comment: 8 pages, 4 figures, 1 table, Submitted to ApJL

We have used the Mid-InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST) to obtain the first spatially resolved, mid-infrared (mid-IR) images of IIZw096, a merging luminous infrared galaxy (LIRG) at $z = 0.036$. Previous observations with the Spitzer Space Telescope suggested that the vast majority of the total IR luminosity (LIR) of the system originated from a small region outside of the two merging nuclei. New observations with JWST/MIRI now allow an accurate measurement of the location and luminosity density of the source that is responsible for the bulk of the IR emission. We estimate that 40-70% of the IR bolometric luminosity, or $3-5 \times 10^{11}\,{\rm{L_{\odot}}}$, arises from a source no larger than 175pc in radius, suggesting a luminosity density of at least $3-5 \times 10^{12} \, {\rm{L_{\odot} \, kpc^{-2}}}$. In addition, we detect 11 other star forming sources, five of which were previously unknown. The MIRI F1500W/F560W colors of most of these sources, including the source responsible for the bulk of the far-IR emission, are much redder than the nuclei of local LIRGs. These observations reveal the power of JWST to disentangle the complex regions at the hearts of merging, dusty galaxies., Comment: 3 figures, 1 table, Accepted for publication in ApJL

We present a rest-frame optical morphological analysis of galaxies observed with the NIRCam imager on the James Webb Space Telescope (JWST) as part of the GLASS-JWST Early Release Science program. We select 388 sources at redshifts \(0.8 < z < 5.4\) and use the seven 0.9--5\micron\ NIRCam filters to generate rest-frame $gri$ composite color images, and conduct visual morphological classification. Compared to HST-based work we find a higher incidence of disks and bulges than expected at $z>1.5$, revealed by rest frame optical imaging. We detect 123 clear disks (58 at $z>1.5$) of which 76 have bulges. No evolution of bulge fraction with redshift is evident: 61\% at \(z<2\) (\(N=110\)) versus 60\% at \(z\geq2\) (\(N=13\)). A stellar mass dependence is evident, with bulges visible in 80\% of all disk galaxies with mass \(> 10^{9.5}\, {\rm M}_{\odot}\) (\(N=41\)) but only 52\% at \(M < 10^{9.5}\, {\rm M}_{\odot}\) (\(N=82\)). We supplement visual morphologies with non-parametric measurements of Gini and Asymmetry coefficients in the rest-frame $i$-band. Our sources are more asymmetric than local galaxies, with slightly higher Gini values. When compared to high-z rest-frame ultraviolet measurements with Hubble Space Telescope, JWST shows more regular morphological types such as disks, bulges and spiral arms at $z>1.5$, with smoother (i.e. lower Gini) and more symmetrical light distributions., Comment: Accepted for publication in ApJ Letters

We report the first gas-phase metallicity map of a distant galaxy measured with the James Webb Space Telescope (JWST). We use the NIRISS slitless spectroscopy acquired by the GLASS Early Release Science program to spatially resolve the rest-frame optical nebular emission lines in a gravitationally lensed galaxy at $z=3.06$ behind the Abell 2744 galaxy cluster. This galaxy (dubbed GLASS-Zgrad1) has stellar mass $\sim10^{8.6} M_\odot$, instantaneous star formation rate $\sim8.6$ $M_\odot$/yr (both corrected for lensing magnification), and global metallicity one-fourth solar. From its emission line maps ([O III], H$\beta$, H$\gamma$, [Ne III], and [O II]) we derive its spatial distribution of gas-phase metallicity using a well-established forward-modeling Bayesian inference method. The exquisite resolution and sensitivity of JWST/NIRISS, combined with lensing magnification, enable us to resolve this $z\sim3$ dwarf galaxy in $\gtrsim$50 resolution elements with sufficient signal, an analysis hitherto not possible. We find that the radial metallicity gradient of GLASS-Zgrad1 is strongly inverted (i.e. positive): $\Delta\log({\rm O/H})/\Delta r$ = $0.165\pm0.023$ $\mathrm{dex~kpc^{-1}}$. This inverted gradient may be due to tidal torques induced by a massive nearby ($\sim$15 kpc projected) galaxy, which can cause inflows of metal-poor gas into the central regions of GLASS-Zgrad1. These first results showcase the power of JWST wide-field slitless spectroscopic modes to resolve the mass assembly and chemical enrichment of low-mass galaxies in and beyond the peak epoch of cosmic star formation ($z\gtrsim2$). Reaching masses $\lesssim 10^9~M_\odot$ at these redshifts is especially valuable to constrain the effects of galactic feedback and environment, and is possible only with JWST's new capabilities., Comment: Accepted to ApJL. 11 pages, 4 figures, and 1 table

We present the first search for $z\geqslant7$, continuum-confirmed sources with NIRISS/WFS spectroscopy over the Abell 2744 Frontier Fields cluster, as part of the GLASS-JWST ERS survey. With $\sim15$ hrs of pre-imaging and multi-angle grism exposures in the F115W, F150W, and F200W filters, we describe the general data handling (i.e., reduction, cleaning, modeling, and extraction processes) and analysis for the GLASS-JWST survey. We showcase the power of JWST to peer deep into reionization, when most intergalactic hydrogen is neutral, by confirming two galaxies at $z=8.04\pm0.15$ and $z=7.90\pm0.13$ by means of their Lyman breaks. Fainter continuum spectra are observed in both the F150W and F200W bands, indicative of blue ($-1.69$ and $-1.33$) UV slopes and moderately-bright absolute magnitudes ($-20.37$ and $-19.68$ mag). We do not detect strong Ly$\alpha$ in either galaxy, but do observe tentative ($\sim2.7-3.8\sigma$) HeII$\lambda$1640 A, OIII]$\lambda\lambda$1661,1666 A, and NIII]$\lambda\lambda$1747,1749 A line emission in one, suggestive of low metallicity, star-forming systems with possible non-thermal contributions. These novel observations provide a first look at the extraordinary potential of JWST/NIRISS for confirming representative samples of bright $z\geqslant7$ sources in the absence of strong emission lines, and gain unprecedented insight into their contributions towards cosmic reionization., Comment: Accepted for publication in ApJL on 1st September 2022, after minor modifications based on the referee report. 10 pages, 3 figures, 1 table

The fourth Fermi Large Area Telescope (LAT) catalog (4FGL) contains 5064 $\gamma$-ray sources detected at high significance, but 26% of them still lack associations at other wavelengths. The SPT-SZ survey, conducted between 2008 and 2011 with the South Pole Telescope (SPT), covers 2500 $\mathrm{deg^2}$ of the Southern sky in three millimeter-wavelength (mm) bands and was used to construct a catalog of nearly 5000 emissive sources. In this study, we introduce a new cross-matching scheme to search for multi-wavelength counterparts of extragalactic $\gamma$-ray sources using a mm catalog. We apply a Poissonian probability to evaluate the rate of spurious false associations and compare the multi-wavelength associations from the radio, mm, near-infrared, and X-ray with 4FGL $\gamma$-ray sources. In the SPT-SZ survey field, 85% of 4FGL sources are associated with mm counterparts. These mm sources include 94% of previously associated 4FGL sources and 56% of previously unassociated 4FGL sources. The latter group contains 40 4FGL sources for which SPT has provided the first identified counterparts. Nearly all of the SPT-associated 4FGL sources can be described as flat-spectrum radio quasars or blazars. We find that the mm band is the most efficient wavelength for detecting $\gamma$-ray blazars when considering both completeness and purity. We also demonstrate that the mm band correlates better to the $\gamma$-ray band than the radio or X-ray bands. With the next generation of CMB experiments, this technique can be extended to greater sensitivities and more sky area to further complete the identifications of the remaining unknown $\gamma$-ray blazars., Comment: 19 pages, 12 figures, 3 tables. published in ApJ

Type 2 active galactic nuclei (AGN) show signatures of accretion onto a supermassive black hole through strong, high-ionization, narrow emission lines extended on scales of 100s to 1000s of parsecs, but they lack the broad emission lines from close in to the black hole that characterize type 1 AGN. The lack of broad emission could indicate obscuration of the innermost nuclear regions, or could indicate that the black hole is no longer strongly accreting. Since high-energy X-rays can penetrate thick obscuring columns, they have the power to distinguish these two scenarios. We present high-energy NuSTAR observations of 9 Seyfert 2 AGN from the IRAS 12 micron survey, supplemented with low-energy X-ray observations from Chandra, XMM-Newton, and Swift. The galaxies were selected to have anomalously low observed 2-10 keV luminosities compared to their [O III] optical luminosities, a traditional diagnostic of heavily obscured AGN, reaching into the Compton-thick regime for the highest hydrogen column densities ($N_{\rm H} > 1.5 \times 10^{24}\, {\rm cm}^{-2}$). Based on updated [O III] luminosities and intrinsic X-ray luminosities based on physical modeling of the hard X-ray spectra, we find that one galaxy was misclassified as type 2 (NGC 5005) and most of the remaining AGN are obscured, including three confirmed as Compton-thick (IC 3639, NGC 1386, and NGC 3982). One galaxy, NGC 3627, appears to be recently deactivated. Compared to the original sample the 9 AGN were selected from, this is a rate of approximately 1%. We also find a new X-ray changing-look AGN in NGC 6890., Comment: 42 pages, Accepted for publication in ApJ

Ultracool dwarfs represent a significant proportion of stars in the Milky Way,and deep samples of these sources have the potential to constrain the formation history and evolution of low-mass objects in the Galaxy. Until recently, spectral samples have been limited to the local volume (d<100 pc). Here, we analyze a sample of 164 spectroscopically-characterized ultracool dwarfs identified by Aganze et al. (2022) in the Hubble Space Telescope WFC3 Infrared Spectroscopic Parallel (WISP) Survey and 3D-HST. We model the observed luminosity function using population simulations to place constraints on scaleheights, vertical velocity dispersions and population ages as a function of spectral type. Our star counts are consistent with a power-law mass function and constant star formation history for ultracool dwarfs, with vertical scaleheights 249$_{-61}^{+48}$ pc for late M dwarfs, 153$_{-30}^{+56}$ pc for L dwarfs, and 175$_{-56}^{+149}$ pc for T dwarfs. Using spatial and velocity dispersion relations, these scaleheights correspond to disk population ages of 3.6$_{-1.0}^{+0.8}$ for late M dwarfs, 2.1$_{-0.5}^{+0.9}$ Gyr for L dwarfs, and 2.4$_{-0.8}^{+2.4}$ Gyr for T dwarfs, which are consistent with prior simulations that predict that L-type dwarfs are on average a younger and less dispersed population. There is an additional 1-2 Gyr systematic uncertainty on these ages due to variances in age-velocity relations. We use our population simulations to predict the UCD yield in the JWST PASSAGES survey, a similar and deeper survey to WISPS and 3D-HST, and find that it will produce a comparably-sized UCD sample, albeit dominated by thick disk and halo sources., Comment: Published in ApJ

We report the first spatially resolved measurements of gas-phase metallicity radial gradients in star-forming galaxies in overdense environments at $z\gtrsim2$. The spectroscopic data are acquired by the \mg\ survey, a Hubble Space Telescope (HST) cycle-28 medium program. This program is obtaining 45 orbits of WFC3/IR grism spectroscopy in the density peak regions of three massive galaxy protoclusters (BOSS 1244, BOSS 1542 and BOSS 1441) at $z=2-3$. Our sample in the BOSS 1244 field consists of 20 galaxies with stellar-mass ranging from $10^{9.0}$ to $10^{10.3}$ \Msun\ , star formation rate (SFR) from 10 to 240 \Msun\,yr$^{-1}$, and global gas-phase metallicity (\oh) from 8.2 to 8.6. At $1\sigma$ confidence level, 2/20 galaxies in our sample show positive (inverted) gradients -- the relative abundance of oxygen increasing with galactocentric radius, opposite the usual trend. Furthermore, 1/20 shows negative gradients and 17/20 are consistent with flat gradients. This high fraction of flat/inverted gradients is uncommon in simulations and previous observations conducted in blank fields at similar redshifts. To understand this, we investigate the correlations among various observed properties of our sample galaxies. We find an anticorrelation between metallicity gradient and global metallicity of our galaxies residing in extreme overdensities, and a marked deficiency of metallicity in our massive galaxies as compared to their coeval field counterparts. We conclude that the cold-mode gas accretion plays an active role in shaping the chemical evolution of galaxies in the protocluster environments, diluting their central chemical abundance, and flattening/inverting their metallicity gradients., Comment: 13 pages, 6 figures, 1 table. Accepted for publication in ApJL

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 SPT0311-58 system at z=6.900 is an extremely massive structure within the reionization epoch, and offers a chance to understand the formation of galaxies in an extreme peak in the primordial density field. We present 70mas Atacama Large Millimeter/submillimeter Array observations of the dust continuum and CII 158um emission in the central pair of galaxies and reach physical resolution ~100-350pc, among the most detailed views of any reionization-era system to date. The observations resolve the source into at least a dozen kiloparsec-size clumps. The global kinematics and high turbulent velocity dispersion within the galaxies present a striking contrast to recent claims of dynamically cold thin-disk kinematics in some dusty galaxies just 800Myr later at z~4. We speculate that both gravitational interactions and fragmentation from massive parent disks have likely played a role in the overall dynamics and formation of clumps in the system. Each clump individually is comparable in mass to other 6

SPT0346-52 (z=5.7) is the most intensely star-forming galaxy discovered by the South Pole Telescope, with Sigma_SFR ~ 4200 Msol yr^-1 kpc^-2. In this paper, we expand on previous spatially-resolved studies, using ALMA observations of dust continuum, [NII]205 micron, [CII]158 micron, [OI]146 micron, and undetected [NII]122 micron and [OI]63 micron emission to study the multi-phase interstellar medium (ISM) in SPT0346-52. We use pixelated, visibility-based lens modeling to reconstruct the source-plane emission. We also model the source-plane emission using the photoionization code CLOUDY and find a supersolar metallicity system. We calculate T_dust = 48.3 K and lambda_peak = 80 micron, and see line deficits in all five lines. The ionized gas is less dense than comparable galaxies, with n_e < 32 cm^-3, while ~20% of the [CII]158 emission originates from the ionized phase of the ISM. We also calculate the masses of several phases of the ISM. We find that molecular gas dominates the mass of the ISM in SPT0346-52, with the molecular gas mass ~4x higher than the neutral atomic gas mass and ~100x higher than the ionized gas mass., Comment: 25 pages, 15 figures. Accepted for publication in ApJ

Despite advances in observational data, theoretical models, and computational techniques to simulate key physical processes in the formation and evolution of galaxies, the stellar mass assembly of galaxies still remains an unsolved problem today. Optical spectroscopic measurements appear to show that the gas-phase metallicities of local ultra-luminous infrared galaxies (ULIRGs) are significantly lower than those of normal star-forming galaxies. This difference has resulted in the claim that ULIRGs are fueled by metal-poor gas accretion from the outskirts\cite{Mannucci10}. Here we report on a new set of gas-phase metallicity measurements making use of the far-infrared spectral lines of [O{\sc iii}]52 $\mu$m, [O{\sc iii}]88 $\mu$m, and [N{\sc iii}]57 $\mu$m instead of the usual optical lines. Photoionization models have resulted in a metallicity diagnostic based on these three lines that break the electron density degeneracy and reduce the scatter of the correlation significantly. Using new data from SOFIA and archival data from Herschel Space Observatory, we find that local ULIRGs lie on the mass-metallicity relation of star-forming galaxies and have metallicities comparable to other galaxies with similar stellar masses and star formation rates. The lack of a departure suggests that ULIRGs follow the same mass assembly mechanism as luminous star-forming galaxies and $\sim 0.3$ dex under-abundance in metallicities derived from optical lines is a result of heavily obscured metal-rich gas which has a negligible effect when using the FIR line diagnostics., Comment: Preprint submitted for publication 10/29/21

We present a Bayesian inference on the neutral hydrogen fraction of the intergalactic medium (IGM), $x_{\textrm{HI}}$, at $z \sim$ 6-8 using the properties of Lyman break galaxies during the Epoch of Reionization. We use large samples of LBG candidates at $5.5 \leq z \leq 8.2$ with spectroscopy from Keck/DEIMOS and Keck/MOSFIRE. For each galaxy, we incorporate either the Lyman-$\alpha$ equivalent width (EW) for detections or the EW limit spectrum for nondetections to parameterize the EW distribution at various ultraviolet brightnesses for a given redshift. Using our reference sample of galaxy candidates from the ionized universe at $z$ $\sim$ 6.0, we are able to infer $x_{\textrm{HI}}$ at two redshifts: $z$ $\sim$ 6.7 and $z$ $\sim$ 7.6. This work includes intrinsically faint, gravitationally lensed galaxies at $z$ $\sim$ 6.0 in order to constrain the intrinsic faint-end Ly$\alpha$ EW distribution and provide a comparable population of galaxies to counterparts in our sample that are at higher redshift. The inclusion of faint galaxy candidates, in addition to a more sophisticated modelling framework, allows us to better isolate effects of the interstellar medium and circumgalactic medium on the observed Lyman-$\alpha$ distribution from those of the IGM. We infer an upper limit of $x_{\textrm{HI}}$ $\leq$ 0.25 at $z$ = 6.7 $\pm$ 0.2 and a neutral fraction of $x_{\textrm{HI}}$ = $0.83^{+0.08}_{-0.11}$ at $z$ = 7.6$\pm$ 0.6, both within 1$\sigma$ uncertainty, results which favor a moderately late and rapid reionization., Comment: 11 pages, 7 figures

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. Targeting active galactic nuclei (AGN) with luminosities of {\lambda}L{\lambda} (5100 {\AA}) = 10^44 erg/s and predicted H{\beta} lags of 20-30 days or black hole masses of 10^7-10^8.5 Msun, 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 H{\beta} emission-line light curves, integrated H{\beta} lag times (8-30 days) measured against V-band continuum light curves, velocity-resolved reverberation lags, line widths of the broad H{\beta} components, and virial black hole mass estimates (10^7.1-10^8.1 Msun). 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., Comment: 34 pages, 14 figures, accepted for publication in ApJ

We present new and archival SOFIA FIFI-LS far-IR spectroscopic observations of 25 local galaxies of either the [OIII]52um and/or the [NIII]57um lines. Including other 31 galaxies from Herschel-PACS, we discuss a local sample of 47 galaxies, including HII region, luminous IR, low-metallicity dwarf and Seyfert galaxies. Analyzing the mid- to far-IR fine-structure lines of this sample, we assess the metallicity and compare with the optical spectroscopy estimates. Using the IR, we find a similar O/H--N/O relation to that known in the optical. As opposite, we find systematically lower N/O IR abundances when compared to the optical determinations, especially at high values of N/O (log(N/O) > -0.8). We explore various hypotheses to account for this difference: (i) difference in ionization structure traced by optical (O+, N+ regions) versus IR lines (O++, N++ regions); (ii) contamination of diffuse ionized gas affecting the optical lines used to compute the N/O abundance; (iii) dust obscuration affecting the optical-based determinations. However, we have not found any correlation of the Delta(N/O)= (N/O)_OPT-(N/O)_IR with either ionization, or electron density, or optical extinction. We speculatively suggest that accretion of metal-poor gas from the circumgalactic medium could provide an explanation for this difference, because the rapid decrease of total abundances during infall is followed by a N/O ratio decrease due to primary production of young - possibly embedded - massive stars, are preferentially traced by the IR diagnostics, while optical diagnostics would better trace the secondary production, when both N/O and O/H abundance ratios will increase., Comment: Accepted in the AstrophysicalJournal on the 7th November 2021

We identify a sample of spectroscopically measured emission line galaxy (ELG) pairs up to z=1.6 from the WFC3 Infrared Spectroscopic Parallels (WISP) survey. WISP obtained slitless, near-infrared grism spectroscopy along with direct imaging in the J and H bands by observing in the pure-parallel mode with the Wide Field Camera Three (WFC3) on the Hubble Space Telescope (HST). From our search of 419 WISP fields covering an area of ~0.5 deg$^{2}$, we find 413 ELG pair systems, mostly Halpha emitters. We then derive reliable star formation rates (SFRs) based on the attenuation-corrected Halpha fluxes. Compared to isolated galaxies, we find an average SFR enhancement of 40%-65%, which is stronger for major pairs and pairs with smaller velocity separations (Delta_v < 300 km/s). Based on the stacked spectra from various subsamples, we study the trends of emission line ratios in pairs, and find a general consistency with enhanced lower-ionization lines. We study the pair fraction among ELGs, and find a marginally significant increase with redshift $f \propto (1+z)^\alpha$, where the power-law index \alpha=0.58$\pm$0.17 from $z\sim$0.2 to $z\sim$1.6. The fraction of Active galactic Nuclei (AGNs), is found to be the same in the ELG pairs as compared to isolated ELGs., Comment: 22 pages, 9 figures, 6 tables, accepted for publication in ApJ

The observed large-scale scatter in Lyman $\alpha$ opacity of the intergalactic medium at $z<6$ implies large fluctuations in the neutral hydrogen fraction that are unexpected long after reionization has ended. A number of models have emerged to explain these fluctuations that make testable predictions for the relationship between Ly$\alpha$ opacity and density. We present selections of $z=5.7$ Ly$\alpha$-emitting galaxies (LAEs) in the fields surrounding two highly opaque quasar sightlines with long Ly$\alpha$ troughs. The fields lie towards the $z=6.0$ quasar ULAS J0148+0600, for which we re-analyze previously published results using improved photometric selection, and towards the $z=6.15$ quasar SDSS J1250+3130, for which results are presented here for the first time. In both fields, we report a deficit of LAEs within 20 $h^{-1}$ Mpc of the quasar. The association of highly opaque sightlines with galaxy underdensities in these two fields is consistent with models in which the scatter in Ly$\alpha$ opacity is driven by large-scale fluctuations in the ionizing UV background, or by an ultra-late reionization that has not yet concluded at $z=5.7$., Comment: Accepted to ApJ. 17 pages, 13 figures

We conducted systematic observations of the H I Br$\alpha$ (4.05 $\mu$m) and Br$\beta$ (2.63 $\mu$m) lines in 52 nearby ($z<0.3$) ultraluminous infrared galaxies (ULIRGs) with AKARI. Among 33 ULIRGs wherein the lines are detected, three galaxies show anomalous Br$\beta$/Br$\alpha$ line ratios ($\sim1.0$), which are significantly higher than those for case B (0.565). Our observations also show that ULIRGs have a tendency to exhibit higher Br$\beta$/Br$\alpha$ line ratios than those observed in Galactic H II regions. The high Br$\beta$/Br$\alpha$ line ratios cannot be explained by a combination of dust extinction and case B since dust extinction reduces the ratio. We explore possible causes for the high Br$\beta$/Br$\alpha$ line ratios and show that the observed ratios can be explained by a combination of an optically thick Br$\alpha$ line and an optically thin Br$\beta$ line. We simulated the H II regions in ULIRGs with the Cloudy code, and our results show that the high Br$\beta$/Br$\alpha$ line ratios can be explained by high-density conditions, wherein the Br$\alpha$ line becomes optically thick. To achieve a column density large enough to make the Br$\alpha$ line optically thick within a single H II region, the gas density must be as high as $n\sim10^8$ $\mathrm{cm}^{-3}$. We therefore propose an ensemble of H II regions, in each of which the Br$\alpha$ line is optically thick, to explain the high Br$\beta$/Br$\alpha$ line ratio., Comment: 28 pages, 15 figures, accepted for publication in ApJ