We present a detailed analysis of J154506, a strongly lensed submillimetre galaxy (SMG) behind the Lupus-I molecular cloud, and a characterisation of its physical properties using a combination of new and archival data, including VLT/MUSE and FORS2 optical data. We identify two high-significance (S/N > 5) emission lines at 97.0 and 145.5 GHz, corresponding to CO(4-3) and CO(6-5), respectively, in spectral scans from the Atacama Compact Array (ACA) and the Large Millimetre Telescope (LMT), as well as the [CII] 158 μm fine-structure line at 400 GHz observed with the Atacama Pathfinder Experiment (APEX). These detections yield a spectroscopic redshift of zspec = 3.7515 ± 0.0005. We also report the detection of [CI], HCN(4-3), and two H2O+ transitions, further confirming the redshift and providing insights into the physical properties of J154506. By modelling sub-arcsecond resolution (0.75″) ALMA Band 6 and 7 continuum data in the uv-plane, we derive an average magnification factor of 6.0 ± 0.4, and our analysis reveals a relatively cold dust (38 K) in a starburst galaxy (∼ 900 M⊙ yr−1) with a high intrinsic dust mass (∼ 2.5 × 109 M⊙) and infrared (IR) luminosity (∼ 6 × 1012 L⊙). Non-local thermodynamic equilibrium radiative transfer modelling of the joint dust spectral energy distribution (SED) and CO line excitation suggests the dust continuum emission is primarily associated with relatively diffuse regions with molecular gas densities of 102−104 cm−3, rather than compact, high-pressure environments typical of extreme starbursts or active galactic nuclei (AGNs). This interpretation is supported by the close-to-unity ratio between the dust and gas kinetic temperatures, which argues against highly energetic heating mechanisms. The CO excitation ladder peaks close to CO(5-4) and is dominated by slightly denser molecular gas. Our results underscore the unique power of far-IR and submillimetre observations to both uncover and characterise scarce, strongly lensed, high-redshift galaxies, even when they are obscured by foreground molecular clouds.

Using a 90 ks Chandra ACIS-S observation in the 0.3–7 keV band, along with complementary Low-Frequency Array and Karl G. Jansky Very Large Array data in the 120–168 MHz and 1–2 GHz ranges, we study the diffuse emission around the nearby dwarf galaxy KUG 1138+327. Our analysis reveals a diffuse X-ray feature on the southern side, disconnected from the galactic disk. This feature exhibits a hard X-ray spectrum, which is highly unusual for an outflow from a dwarf galaxy. We interpret the irregularly shaped feature as hot plasma in a young galaxy cluster at redshift 0.5, supported by X-ray spectral fitting and consistent with the optical redshift of the central elliptical galaxy of a known cluster identified by a red sequence. Additionally, we detect a radio lobe east of the X-ray feature, likely produced by an active galactic nucleus (AGN) offset from the cluster center and confined primarily by ram pressure from the ambient medium. The lobe shows a steep nonthermal radio spectrum, suggesting a cosmic-ray age of ≳5 × 10 ^7 yr. Assuming energy equipartition between cosmic rays and magnetic fields, we estimate the lobe’s total energy to be ∼9 × 10 ^56 erg, comparable to the thermal energy in the same volume. This study thus identifies a background young cluster projected next to KUG 1138+327 and highlights the potentially significant role of off-center AGN feedback in shaping the intracluster medium.

Investigating the processes by which galaxies rapidly build up their stellar mass during the peak of their star formation ( z = 2–3) is crucial to advancing our understanding of the assembly of large-scale structures. We report the discovery of one of the most gas- and dust-rich protocluster core candidates, PJ0846+15 (J0846), from the Planck All-Sky Survey to Analyze Gravitationally lensed Extreme Starbursts (PASSAGES) sample. The exceedingly high total star formation rate (SFR) uncorrected for lensing magnification ( μ ) of μ SFR = 3990 0 − 12900 + 23000 M ⊙ yr −1 is the result of a foreground cluster lensing at least 11 dusty star-forming galaxies between z = 2.660 and 2.669, where the intrinsic value is estimated to be SFR = 520 0 − 2000 + 3200 M ⊙ yr −1 . Atacama Large Millimeter/submillimeter Array observations uncovered 18 CO(3–2) emission-line detections, some of which are multiply imaged systems, lensed by a foreground cluster at z = 0.77. We present the first multiwavelength characterization of this field, constructing a lens model that predicts that these 11 galaxies ( μ ≃ 1.5–25) are contained within a projected physical extent of 280 × 150 kpc, with a velocity dispersion of σ v = 246 ± 72 km s −1 . J0846 exhibits the rare case of a protocluster candidate whose core is strongly lensed, offering a magnified view of the rapid stellar buildup within an overdense environment at Cosmic Noon.

We present JWST-NIRCam narrowband, 4.05 μ m Br α images of the Sgr C H ii region, located in the central molecular zone (CMZ) of the Galaxy. Unlike any H ii region in the solar vicinity, the Sgr C plasma is dominated by filamentary structure in both Br α and the radio continuum. Some bright filaments, which form a fractured arc with a radius of about 1.85 pc centered on the Sgr C star-forming molecular clump, likely trace ionization fronts. The brightest filaments form a “ π -shaped” structure in the center of the H ii region. Fainter filaments radiate away from the surface of the Sgr C molecular cloud. The filaments are emitting optically thin free–free emission, as revealed by spectral index measurements from 1.28 GHz (MeerKAT) to 97 GHz (Atacama Large Millimeter/submillimeter Array). But, the negative in-band 1 to 2 GHz spectral index in the MeerKAT data alone reveals the presence of a nonthermal component across the entire Sgr C H ii region. We argue that the plasma flow in Sgr C is controlled by magnetic fields, which confine the plasma to ropelike filaments or sheets. This results in the measured nonthermal component of low-frequency radio emission plasma, as well as a plasma β (thermal pressure divided by magnetic pressure) below 1, even in the densest regions. We speculate that all mature H ii regions in the CMZ, and galactic nuclei in general, evolve in a magnetically dominated, low plasma β regime.

We explore what unusual products a starburst of about 6% solar metallicity and a mean estimated age of ∼5 × 10 ^5 yr can produce in KUG 1138+327 at a distance of 24.5 Mpc. Chandra X-ray observations show a dominant point-like source with an average 0.3–10 keV luminosity of 10 ^40.3 erg s ^−1 and variability by a factor of ∼2 over months. This extreme ultraluminous X-ray source (ULX) is apparently associated with the young central cluster. A multicolor disk modeling of the X-ray spectrum of the source suggests a standard accretion around a black hole. It also has a morphologically elongated nonthermal radio continuum counterpart on the scale of ∼200 pc, probably the longest detected from such a source. The radio, optical, and X-ray findings suggest that it could well be an intermediate-mass black hole undergoing sub-Eddington accretion from a massive star companion. Accounting for the presence of the ULX and the prominent emission lines He II λ 4658 and [Ar IV ] λ 4711 while lacking Wolf–Rayet spectral features, we estimate the true age of the starburst to be about 2–4 Myr. Only with such a moderate age can the starburst host this extraordinary ULX, probably triggered by a recent influx of extremely low-metallicity gas. This study demonstrates the potential of multiwavelength studies of low-metallicity starbursts to provide insights into what may commonly occur in high-redshift galaxies.

With a new joint-deconvolution pipeline, we combine the single-dish and interferometric atomic hydrogen (H i ) data of M51 observed by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) (FEASTS program) and the Very Large Array (VLA) (THINGS). The product data cube has a typical line width of 13 km s ^−1 and a 2 σ line-of-sight (LOS) sensitivity of H i column density N _H _i ∼ 3.2 × 18 cm ^−2 at a spatial resolution of ∼18″ (∼0.7 kpc). Among the H i detected LOSs extending to ∼50 kpc, ∼89% consist of diffuse H i only, which is missed by previous VLA observations. The distribution of dense H i is reproduced by previous hydrodynamical simulations of this system, but the diffuse component is not, likely due to unresolved physics related to the interaction between the circumgalactic and interstellar media. With simple models, we find that these low N _H _i structures could survive the background ultraviolet photoionization, but are susceptible to the thermal evaporation. We find a positive correlation between LOS velocity dispersion ( σ _v ) and N _H _i with a logarithmic index of ∼0.5. Based on existing turbulent mixing layer (TML) theories and simulations, we propose a scenario of hot gas cooling and accreting onto the disk through a TML, which could reproduce the observed power index of ∼0.5. We estimate the related cooling and accretion rates to be roughly one-third to two-thirds of the star formation rate. A typical column density of diffuse H i (∼10 ^19 cm ^−2 ) can be accreted within 300 Myr, the interaction timescale previously estimated for the system. Such a gas accretion channel has been overlooked before, and may be important for gas-rich interacting systems and for high-redshift galaxy evolution.

Context. Molecular gas, which serves as the fuel for star formation, and its relationship with atomic gas are essential for understanding how galaxies regulate their star forming activities. Aims. We conducted IRAM 30 m observations of 23 nearby spiral galaxies as part of the CHANG-ES project to investigate the distribution of molecular gas and the Kennicutt-Schmidt star formation law in these galaxies. By combining these results with atomic gas masses studied in previous work, we aim to investigate the scaling relations that connect the molecular and atomic gas masses with stellar masses and the baryonic Tully-Fisher relation. Methods. Based on spatially resolved observations of the 12CO J = 1 - 0, 13CO J = 1 - 0, and 12CO J = 2 - 1 molecular lines, we calculated the total molecular gas masses, obtained the ratios between different CO lines, and derived some key physical parameters, such as the temperature and optical depth of the molecular gas. Results. For the nuclear and disc regions, the median values of the 12CO/13CO J = 1 - 0 line ratio are 8.6 and 6.1, respectively, while those of the 12CO J = 2 - 1/J = 1 - 0 line ratio are 0.53 and 0.39. The molecular gas mass derived from 13CO J = 1 - 0 is strongly correlated with but systematically lower than that derived from 12CO J = 1 - 0. Most of the galaxies in our sample follow the spatially resolved star forming scaling relation between the star formation rate surface density and molecular gas mass surface density, with a median gas depletion time scale of similar to 1 Gyr. A few galaxies exhibit enhanced star formation efficiency, with shorter time scales of similar to 0.1 Gyr. Our sample shows a weak correlation between molecular and atomic gas but a strong correlation between the molecular-to-atomic gas mass ratio (MH2/MHI) and stellar mass, consistent with previous studies. Galaxies with lower stellar masses in our sample exhibit an excess of atomic gas by one magnitude compared to molecular gas, suggesting that the transformation of atomic gas into molecular gas is less efficient. Most galaxies tightly follow the baryonic Tully-Fisher relation, but NGC 2992 and NGC 4594 deviate from the relation due to different physical factors. We find that the ratio of the cold gas (comprising molecular and atomic gas) to the total baryon mass decreases with the gravitational potential of the galaxy, as traced by rotation velocity, which could be due to gas consumption in star formation or being heated to the hot phase.

Radio halos of edge-on galaxies are crucial for investigating cosmic ray propagation and magnetic field structures in galactic environments. We present VLA C-configuration S-band (2-4 GHz) observations of the spiral galaxy NGC 3556, a target from the Continuum Halos in Nearby Galaxies-an EVLA Survey. We estimate the thermal contribution to the radio emission from a combination of the H alpha and mid-IR data, and employ rotation measure synthesis to reveal the magnetic field structures. In our data, NGC 3556 exhibits a box-like radio halo extending nearly 7 kpc from the galactic plane. The scale height of the total S-band intensity in the halo is 1.68 +/- 0.29 kpc, while that of the nonthermal intensity is 1.93 +/- 0.28 kpc. Fitting the data to a 1D cosmic-ray transport model, we find advection to describe the cosmic-ray propagation within the halo better than diffusion, with advection speeds of 245 +/- 15 km s-1 and 205 +/- 25 km s-1 above and below the disk, respectively. The magnetic field is detected patchily across the galaxy, displaying a toroidal configuration in the rotation measure map. The mean equipartition magnetic field strength is approximately 8.3 mu G in the disk and 4.5 mu G in the halo. In addition, a bubble-like structure extends nearly 3 kpc into the southern halo, aligned with the polarized intensity and H alpha image, suggestive of superwinds generated by recent star formation feedback in the nuclear region.

We analyze the CS ( J = 2-1 ) line cube from the internal data release obtained by the large-scale program "ALMA CMZ Exploration Survey ( ACES ) " to investigate the kinematic structure of the innermost similar to 10 pc region of the Galaxy, which contains the high-velocity compact cloud (HVCC) at (l, b, vLSR) similar to(+0 .degrees 02, -0 .degrees 02, 100 km s-1) ( hereafter G0.02 ) . The longitude-velocity diagram (LVD) of the cloud draws an elliptical structure, which is interpreted as an orbital trajectory in the (l, vLSR) space of a noncircular ( eccentric ) motion of the molecular gas in the gravitational potential of an extended mass distribution in the central 10 pc of the Galaxy. We argue that G0.02 is a kinematic tracer of the inner potential, a rare case of a dense an eccentric orbit in the nuclear field.

X-ray observations can be used to effectively probe the galactic ecosystem, particularly its hot and energetic components. However, existing X-ray studies of nearby star-forming galaxies are limited by insufficient data statistics and a lack of suitable spectral modeling to account for X-ray emission and absorption geometry. We present results from an X-ray spectral study of M51 using 1.3 Ms Chandra data, the most extensive for such a galaxy. This allows the extraction of diffuse X-ray emission spectra from phase-dependent regions of spiral arms using a logarithmic spiral coordinate system. A hierarchical Bayesian approach analyzes these spectra, testing models from simple single-temperature hot plasma to those including distributed hot plasma and X-ray-absorbing cool gas. We recommend a model that fits the spectra well, featuring a galactic corona with a lognormal temperature distribution and a disk with mixed X-ray emissions and absorption. In this model, only half of the coronal emission is subject to internal absorption. The best-fit column density of absorbing gas is roughly twice that inferred from optical extinction of stellar light. The temperature distribution shows a mean temperature of ∼0.1 keV and an average one-dex dispersion that is enhanced on the spiral arms. The corona’s radiative cooling might balance the mechanical energy input from stellar feedback. These results highlight the effectiveness of X-ray mapping of the corona and cool gas in spiral galaxies.

Context. High-redshift radio(-loud) galaxies (HzRGs) are massive galaxies with powerful radio-loud active galactic nuclei (AGNs) and serve as beacons for protocluster identification. However, the interplay between HzRGs and the large-scale environment remains unclear. Aims. To understand the connection between HzRGs and the surrounding obscured star formation, we investigated the overdensity and spatial distribution of submillimeter-bright galaxies (SMGs) in the field of 4C 23.56, a well-known HzRG at z = 2.48. Methods. We used SCUBA-2 data (sigma similar to 0.6 mJy) to estimate the 850 mu m source number counts and examine the radial and azimuthal overdensities of the 850 mu m sources in the vicinity of the HzRG. Results. The angular distribution of SMGs is inhomogeneous around the HzRG 4C 23.56, with fewer sources oriented along the radio jet. We also find a significant overdensity of bright SMGs (S-850 mu m >= 5 mJy). Faint and bright SMGs exhibit different spatial distributions. The former are concentrated in the core region, while the latter prefer the outskirts of the HzRG field. High-resolution observations show that the seven brightest SMGs in our sample are intrinsically bright, suggesting that the overdensity of bright SMGs is less likely due to the source multiplicity.

Sagittarius A East is a supernova remnant with a unique surrounding environment, as it is located in the immediate vicinity of the supermassive black hole at the Galactic center, Sagittarius A*. The X-ray emission of the remnant is suspected to show features of overionized plasma, which would require peculiar evolutionary paths. We report on the first observation of Sagittarius A East with the X-Ray Imaging and Spectroscopy Mission(XRISM). Equipped with a combination of a high-resolution microcalorimeter spectrometer and a large field-of-view CCD imager, we for the first time resolved the Fe XXV K-shell lines into fine structure lines and measured the forbidden-to-resonance intensity ratio to be 1.39 +/- 0.12, which strongly suggests the presence of overionized plasma. We obtained a reliable constraint on the ionization temperature just before the transition into the overionization state, of > 4 keV. The recombination timescale was constrained to be < 8 x10(11) cm(-3) s. The small velocity dispersion of 109 +/- 6 km s(-1) indicates a low Fe ion temperature < 8 keV and a small expansion velocity < 200 km s(-1). The high initial ionization temperature and small recombination timescale suggest that either rapid cooling of the plasma via adiabatic expansion from dense circumstellar material or intense photoionization by Sagittarius A* in the past may have triggered the overionization.

Hydrodynamic simulations of the stellar winds from Wolf-Rayet stars within the Galactic Center can provide predictions for the X-ray spectrum of supermassive black hole Sgr A*. Herein, we present results from updated smooth particle hydrodynamics simulations, building on the architecture of Cuadra et al. (2015); Russell et al. (2017), finding that a cold gas disk forms around Sgr A* with a simulation runtime of 3500 years. This result is consistent with previous grid-based simulations, demonstrating that a cold disk can form regardless of numerical method. We examine the plasma scenarios arising from an environment with and without this cold disk, by generating synthetic spectra for comparison to the quiescent Fe K alpha Sgr A* spectrum from Chandra HETG-S, taken through the Chandra X-ray Visionary Program. We find that current and future X-ray missions are unlikely to distinguish between the kinematic signatures in the plasma in these two scenarios. Nonetheless, the stellar wind plasma model presents a good fit to the dispersed Chandra spectra within 1.5" of Sgr A*. We compare our results to the Radiatively Inefficient Accretion Flow (RIAF) model fit to the HETG-S spectrum presented in Paper I and find that the Bayesian model evidence does not strongly favor either model. With 9" angular resolution and high spectral resolution of the X-IFU, NewAthena will offer a clearer differentiation between the RIAF plasma model and hydrodynamic simulations, but only a future X-ray mission with arcsecond resolution will significantly advance our understanding of Sgr A*'s accretion flow in X-rays.

The extreme low-luminosity supermassive black hole Sgr A* provides a unique laboratory in which to test radiatively inefficient accretion flow (RIAF) models. Previous fits to the quiescent Chandra ACIS-S spectrum found a RIAF model with an equal inflow-outflow balance works well. In this work, we apply the RIAF model to the Chandra HETG-S spectrum obtained through the Chandra X-ray Visionary Program, which displays features suggestive of temperature and velocity structures within the plasma. A comprehensive forward model analysis accounting for the accretion flow geometry and HETG-S instrumental effects is required for a full interpretation of the quiescent Chandra HETG-S spectrum. We present a RIAF model that takes these effects into account. Our fits to the high-resolution gratings spectrum indicate an inflow balanced by an outflow ($s \sim 1$) alongside a temperature profile that appears shallower than what would be expected from a gravitational potential following $1/r$. The data require that the abundance of Iron relative to solar is $Z_{Fe} < 0.32 Z_\odot$ (90\% credible interval), much lower than the $2~Z_\odot$ metallicity measured in nearby late-type giants. While future missions like NewAthena will provide higher spectral resolution, source separation will continue to be a problem. Leveraging Chandra's unparalleled spatial resolution, which is not expected to be surpassed for decades, remains essential for detailed investigations of the densely populated Galactic Center in X-rays.

Hyperluminous infrared galaxies (HyLIRGs) are the rarest and most extreme starbursts and found only in the distant Universe (z greater than or similar to 1). They have intrinsic infrared (IR) luminosities L-IR >= 10(13) L-circle dot and are commonly found to be major mergers. Recently, the Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts project (PASSAGES) searched similar to 10(4) deg(2) of the sky and found similar to 20 HyLIRGs. We describe a detailed study of PJ0116-24, the brightest (mu(LIR) approximate to 2.6 x 10(14) L-circle dot, magnified with mu approximate to 17) Einstein-ring HyLIRG in the southern sky, at z = 2.125, with observations from the near-IR integral-field spectrograph VLT/ERIS and the submillimetre interferometer ALMA. We detected H alpha, H beta, [N II] and [S II] lines and obtained an extreme Balmer decrement (H alpha/H beta approximate to 8.73 +/- 1.14). We modelled the molecular-gas and ionized-gas kinematics with CO(3-2) and H alpha data at similar to 100-300 pc and (sub)kiloparsec delensed scales, respectively, finding consistent regular rotation. We found PJ0116-24 to be highly rotationally supported (v(rot)/sigma(0, mol. gas) approximate to 9.4) with a richer gaseous substructure than other known HyLIRGs. Our results imply that PJ0116-24 is an intrinsically massive (M-baryon approximate to 10(11.3) M-circle dot) and rare starbursty disk (star-formation rate, SFR = 1,490 M-circle dot yr(-1)) probably undergoing secular evolution. This indicates that the maximal SFR (greater than or similar to 1,000 M-circle dot yr(-1)) predicted by simulations could occur during a galaxy's secular evolution, away from major mergers.

Context. The kinematic information of the extraplanar diffuse ionized gas (eDIG) around galaxies provides clues to the origin of the gas. Aims. The eDIG-CHANGES project studies the physical and kinematic properties of the eDIG around the CHANG-ES sample of nearby edge-on disk galaxies. Methods. We use a novel multi-slit narrow-band spectroscopy technique to obtain the spatial distribution of the spectral properties of the ionized gas around NGC 891, which is often regarded as an analogue of the Milky Way. We developed specific data reduction procedures for the multi-slit narrow-band spectroscopy data taken with the MDM 2.4 m telescope. The data presented in this paper cover the H alpha and [N II]lambda lambda 6548, 6583 & Aring; emission lines. Results. The eDIG traced by the H alpha and [N II] lines shows an obvious asymmetric morphology, being brighter in the northeastern part of the galactic disk and extending a few kiloparsecs above and below the disk. Global variations in the [N II]/H alpha line ratio suggest additional heating mechanisms for the eDIG at large heights beyond photoionization. We also construct position-velocity (PV) diagrams of the eDIG based on our optical multi-slit spectroscopy data and compare them to similar PV diagrams constructed with the H I data. The dynamics of the two gas phases are generally consistent with each other. Modelling the rotation curves at different heights from the galactic mid-plane suggests a vertical negative gradient in turnover radius and maximum rotation velocity, with magnitudes of approximately 3 kpc kpc(-1) and 22 - 25 km s(-1) kpc(-1), respectively. Conclusions. Our measured vertical gradients of the rotation curve parameters suggest significant differential rotation of the ionized gas in the halo, often referred to as the lagging eDIG. Systematic study of the lagging eDIG, using the multi-slit narrow-band spectroscopy technique developed in our eDIG-CHANGES project, will help us to better understand the dynamics of the ionized gas in the halo.

The extraplanar diffuse ionized gas (eDIG) represents ionized gases traced by optical/UV lines beyond the stellar extent of galaxies. We herein introduce a novel multislit narrow-band spectroscopy method to conduct spatially resolved spectroscopy of the eDIG around a sample of nearby edge-on disk galaxies (eDIG-CHANGES). In this paper, we introduce the project design and major scientific goals, as well as a pilot study of NGC 3556 (M108). The eDIG is detected to a vertical extent of a few kiloparsecs above the disk, comparable to the X-ray and radio images. We do not see significant vertical variation of the [N ii ]/H α line ratio. A rough examination of the pressure balance between different circumgalactic medium phases indicates the magnetic field is in a rough pressure balance with the X-ray emitting hot gas and may play an important role in the global motion of both the eDIG and the hot gas in the lower halo. At the location of an Hubble Space Telescope/Cosmic Origins Spectrograph observed UV bright background active galactic nucleus ∼29 kpc from the center of NGC 3556, the magnetic pressure is much lower than that of the hot gas and the ionized gas traced by UV absorption lines, although the extrapolation of the pressure profiles may cause some biases in this comparison. By comparing the position–velocity diagrams of the optical and CO lines, we also find the dynamics of the two gas phases are consistent with each other, with no evidence of a global inflow/outflow and a maximum rotation velocity of ∼150 km s −1 .

The hot, X-ray-emitting phase of the circumgalactic medium of massive galaxies is believed to be the reservoir of baryons from which gas flows onto the central galaxy and into which feedback from active galactic nuclei and stars inject mass, momentum, energy, and metals. These effects shape the velocity fields of the hot gas, which can be observed via the Doppler shifting and broadening of emission lines by X-ray integral field units. In this work, we analyze the gas kinematics of the hot circumgalactic medium of Milky Way–mass disk galaxies from the TNG50 simulation with synthetic observations to determine how future instruments can probe this velocity structure. We find that the hot phase is often characterized by outflows from the disk driven by feedback processes, radial inflows near the galactic plane, and rotation, although in some systems the velocity field is more disorganized and turbulent. With a spectral resolution of ∼1 eV, fast and hot outflows (∼200–500 km s ^−1 ) can be measured, depending on the orientation of the galaxy on the sky. The rotation velocity of the hot phase (∼100–200 km s ^−1 ) can be measured using line shifts in edge-on galaxies, and is slower than that of colder gas phases but similar to stellar rotation velocities. By contrast, the slow inflows (∼50–100 km s ^−1 ) are difficult to measure in projection with these other components, but may be detected in multicomponent spectral fits. We find that the velocity measured is sensitive to which emission lines are used. Measuring these flows will constrain theories of how the gas in these galaxies evolves.

We present a new parametric lens model for the G165.7+67.0 galaxy cluster, which was discovered with $Planck$ through its bright submillimeter flux, originating from a pair of extraordinary dusty star-forming galaxies (DSFGs) at $z\approx 2.2$. Using JWST and interferometric mm/radio observations, we characterize the intrinsic physical properties of the DSFGs, which are separated by only $\sim 1^{\prime\prime}$ (8 kpc) and a velocity difference $\Delta V \lesssim 600~{\rm km}~{\rm s}^{-1}$ in the source plane, and thus likely undergoing a major merger. Boasting intrinsic star formation rates ${\rm SFR}_{\rm IR} = 320 \pm 70$ and $400 \pm 80~ M_\odot~{\rm yr}^{-1}$, stellar masses ${\rm log}[M_\star/M_\odot] = 10.2 \pm 0.1$ and $10.3 \pm 0.1$, and dust attenuations $A_V = 1.5 \pm 0.3$ and $1.2 \pm 0.3$, they are remarkably similar objects. We perform spatially-resolved pixel-by-pixel SED fitting using rest-frame near-UV to near-IR imaging from JWST/NIRCam for both galaxies, resolving some stellar structures down to 100 pc scales. Based on their resolved specific SFRs and $UVJ$ colors, both DSFGs are experiencing significant galaxy-scale star formation events. If they are indeed interacting gravitationally, this strong starburst could be the hallmark of gas that has been disrupted by an initial close passage. In contrast, the host galaxy of the recently discovered triply-imaged SN H0pe has a much lower SFR than the DSFGs, and we present evidence for the onset of inside-out quenching and large column densities of dust even in regions of low specific SFR. Based on the intrinsic SFRs of the DSFGs inferred from UV through FIR SED modeling, this pair of objects alone is predicted to yield an observable $1.1 \pm 0.2~{\rm CCSNe~yr}^{-1}$, making this cluster field ripe for continued monitoring.

We have carried out spatially resolved thermal-nonthermal separation on two edge-on galaxies, NGC 3044 and NGC 5775, using only radio data. Narrowband imaging within a frequency band that is almost contiguous from 1.25 to 7.02 GHz (L band, S band, and C band) has allowed us to fit spectra and construct thermal, nonthermal, and nonthermal spectral index maps. This method does not require any ancillary H alpha and IR data or rely on dust corrections that are challenging in edge-on galaxies. For NGC 3044, at 15 '' resolution, we find a median thermal fraction of similar to 13% with an estimated uncertainty in this fraction of similar to 50% at 4.13 GHz. This compares well with the H alpha mixture method results. We uncovered evidence for a vertical outflow feature reaching at least z similar to 3.5 kpc in projection above the plane, reminiscent of M82's starburst wind. For the higher star formation rate galaxy, NGC 5775, at 12 '' resolution, we find a median thermal fraction of 44% at 4.13 GHz with an estimated error on this fraction of 17%. Both galaxies show a change of slope (flattening) in L band. These results suggest that a radio-only method for separating thermal from nonthermal emission is not only feasible, but able to reveal new features that might otherwise be obscured in edge-on disks.