Field Unit Research Articles

The asymmetric bipolar [Fe II] jet and H2 outflow of TMC1A resolved with the JWST NIRSpec Integral Field Unit

Protostellar outflows exhibit large variations in their structure depending on the observed gas emission. To understand the origin of the observed variations, it is important to analyze the differences in the observed morphology and kinematics of the different tracers. The James Webb Space Telescope (JWST) allows us to study the physical structure of the protostellar outflow through well-known near-infrared shock tracers in a manner unrivaled by other existing ground-based and space-based telescopes at these wavelengths. This study analyzes the atomic jet and molecular outflow in the Class I protostar, TMC1A, utilizing spatially resolved Fe II and H2 lines to characterize the morphology and to identify previously undetected spatial features, and compare them to existing observations of TMC1A and its outflows observed at other wavelengths. We identified a large number of Fe II and H2 lines within the G140H, G235H, and G395H gratings of the NIRSpec IFU observations. We analyzed their morphology and position-velocity (PV) diagrams. From the observed Fe II line ratios, the extinction toward the jet is estimated. We detected the bipolar Fe jet by revealing, for the first time, the presence of a redshifted atomic jet. Similarly, the redshifted component of the H2 slower wide-angle outflow was observed. The Fe II and H2 redhifted emission both exhibit significantly lower flux densities compared to their blueshifted counterparts. Additionally, we report the detection of a collimated high-velocity ($ 100$ km $), blueshifted H2 outflow, suggesting the presence of a molecular jet in addition to the well-known wider angle low-velocity structure. The Fe II and H2 jets show multiple intensity peaks along the jet axis, which may be associated with ongoing or recent outburst events. In addition to the variation in their intensities, the H2 wide-angle outflow exhibits a ring-like structure. The blueshifted H2 outflow also shows a left-right brightness asymmetry likely due to interactions with the surrounding ambient medium and molecular outflows. Using the Fe II line ratios, the extinction along the atomic jet is estimated to be between $A_ V $ = 10--30 on the blueshifted side, with a trend of decreasing extinction with distance from the protostar. A similar $A_ V $ is found for the redshifted side, supporting the argument for an intrinsic red-blue outflow lobe asymmetry rather than environmental effects such as extinction. This intrinsic difference revealed by the unprecedented sensitivity of JWST, suggests that younger outflows already exhibit the red-blue side asymmetry more commonly observed toward jets associated with Class II disks.

Spatially resolved spectroscopic observations of gas emission in dwarf galaxies hosting accreting black hole candidate

ABSTRACT Recent studies on dwarf galaxies reveal that some of them harbour a massive black hole (BH), which is believed to have a similar mass of the supermassive BH ‘seeds’ at early times. The origin and growth of the primitive BHs are still open questions, since these BH seeds are hardly observed at high redshifts. Therefore, MBH of dwarf galaxies can be the perfect candidates to untangle BH ‘seeds’ properties and their influence on their host galaxy evolution, since MBH may preserve their initial conditions due to its quiet merger and accretion histories. We use optical integral field unit observations, obtained with the Gemini GMOS-IFU, to study the gas emission and kinematics in four dwarf galaxies, candidates to host MBH, based on the analysis of their [Fe x] luminosities measured from SDSS spectra. The [Fe x] emission line is not detected in our GMOS in any of the galaxies, prompting speculation that its absence in our recent data may stem from a past tidal disruption event coinciding with the observation period of the SDSS data. All galaxies exhibit extended gas emissions, and the spatially resolved emission-line ratio diagnostic diagrams present values that suggest active galactic nuclei (AGN) photoionization from the [S ii]–BPT diagram. The gas velocity fields of all galaxies are indicative of disturbed rotation patterns, with no detection of gas outflows in any of the sources. Although the [S ii]–BPT diagrams indicate AGN photoionization, further confirmation through multiwavelength observations is required to validate this scenario.

Mid-infrared Fine Structure Lines from the Galactic Warm Ionized Medium

The Warm Ionized Medium (WIM) hosts most of the ionized gas in the Galaxy and occupies perhaps a quarter of the volume of the Galactic disk. Decoding the spectrum of the Galactic diffuse ionizing field is of fundamental interest. This can be done via direct measurements of ionization fractions of various elements. Based on current physical models for the WIM we predicted that mid-IR fine structure lines of Ne, Ar and S would be within the grasp of the Mid-Infrared Imager-Medium Resolution Spectrometer (MIRI-MRS), an Integral Field Unit (IFU) spectrograph, aboard the James Webb Space Telescope (JWST). Motivated thus we analyzed a pair of commissioning data sets and detected [Ne ii] 12.81 μm, [S iii] 18.71 μm and possibly [S iv] 10.51 μm. The inferred emission measure for these detections is about 10 cm−6 pc, typical of the WIM. These detections are broadly consistent with expectations of physical models for the WIM. The current detections are limited by uncorrected fringing (and to a lesser extent by baseline variations). In due course, we expect, as with other IFUs, the calibration pipeline to deliver photon-noise-limited spectra. The detections reported here bode well for the study of the WIM. Along most lines-of-sight hour-long MIRI-MRS observations should detect line emission from the WIM. When combined with optical observations by modern IFUs with high spectral resolution on large ground-based telescopes, the ionization fraction and temperature of neon and sulfur can be robustly inferred. Separately, the ionization of helium in the WIM can be probed by NIRspec. Finally, joint JWST and optical IFU studies will open up a new cottage industry of studying the WIM on arcsecond scales.

Properties of the Line-of-sight Velocity Field in the Hot and X-Ray-emitting Circumgalactic Medium of Nearby Simulated Disk Galaxies

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.

Life cycle assessment of the Athena X-ray integral field unit

Life cycle assessment of the Athena X-ray integral field unit

Investigating Protostellar Accretion-driven Outflows across the Mass Spectrum: JWST NIRSpec Integral Field Unit 3–5 μm Spectral Mapping of Five Young Protostars

Investigating Protostellar Accretion is a Cycle 1 JWST program using the NIRSpec+MIRI integral field units to obtain 2.9–28 μm spectral cubes of five young protostars with luminosities of 0.2–10,000 L ⊙ in their primary accretion phase. This paper introduces the NIRSpec 2.9–5.3 μm data of the inner 840–9000 au with spatial resolutions from 28 to 300 au. The spectra show rising continuum emission; deep ice absorption; emission from H2, H i, and [Fe ii]; and the CO fundamental series in emission and absorption. Maps of the continuum emission show scattered light cavities for all five protostars. In the cavities, collimated jets are detected in [Fe ii] for the four <320 L ⊙ protostars, two of which are additionally traced in Brα. Knots of [Fe ii] emission are detected toward the most luminous protostar, and knots of [Fe ii] emission with dynamical times of <30 yr are found in the jets of the others. While only one jet is traced in H2, knots of H2 and CO are detected in the jets of four protostars. H2 is seen extending through the cavities, showing that they are filled by warm molecular gas. Bright H2 emission is seen along the walls of a single cavity, while in three cavities narrow shells of H2 emission are found, one of which has an [Fe ii] knot at its apex. These data show cavities containing collimated jets traced in atomic/ionic gas surrounded by warm molecular gas in a wide-angle wind and/or gas accelerated by bow shocks in the jets.

Physical Neighbor Crosstalk in Time Division Multiplexed SQUID Arrays for TES Readout

Time division SQUID multiplexing is being developed as the TES readout technology for the ATHENA X-ray integral field unit and CMB-S4. Close packing of TDM and dc-biased SQUID components is motivated by chip area constraints but has resulted in significant physical neighbor crosstalk in previous generation chips. We present techniques to reduce physical neighbor crosstalk in both linear and two dimensional (2D) TDM chips as well as measurements of crosstalk in these chips.

Stellar populations and merger rates of brightest cluster galaxies a billion years ago: SDSS MaNGA IFU spectroscopy

ABSTRACT We investigate the spectroscopic properties of 85 brightest cluster galaxies (BCGs) and their companions observed with the SDSS MaNGA integral field unit. Galaxy redshifts are between 0.08 &amp;lt; z &amp;lt; 0.15, allowing for a field-of-view up to 80 × 80 kpc. For the main galaxies: the average age of the BCG cores is 7.66$\, \pm \,$1.36 Gyr with no significant gradient out to $2\, R_ {e}$; the average metallicity of the BCG cores is $[Z/H]=0.23\, \pm \, 0.03$ with a negative gradient of Δ[Z/H]/Δ(R/Re) = –0.14$\, \pm \, 0.09$ which flattens beyond $1.2\, R_ {e}$. Velocity dispersion gradients are mostly flat, but a few positive slopes are seen in the most massive galaxies. Emission lines are present in 12 of the BCGs, most often confined to the central $\sim 2\,$ kpc with emission line ratios well-described by a LINER or AGN excitation source. There are 78 companion galaxies identified and 9 have nebular emission lines that indicate recent star formation. The companions with flux ratios of 4:1 and 20:1 within 30 kpc of their BCG’s core are studied. The companion galaxies have a median age of 7.65$\, \pm \,$1.55 Gyr and are high-metallicity systems, with a median [Z/H] = 0.17 ± 0.07. Close spectroscopic companions with higher merging probabilities have an average merging time of 0.5 ± 0.2 Gyr. The average merger rate is 0.08$\, \pm \, 0.12 \,$ Gyr−1 for 4:1 companions and 0.26$\, \pm \, 0.22 \,$ Gyr−1 for 20:1 companions, allowing for an increase in mass of 2.3$\, \pm \,$3.4 per cent Gyr−1 and 3.5$\, \pm \,$3.2 per cent Gyr−1, respectively.

Thermalization of Mesh Reinforced Ultra-Thin Al-Coated Plastic Films: A Parametric Study Applied to the Athena X-IFU Instrument.

The X-ray Integral Field Unit (X-IFU) is one of the two focal plane detectors of Athena, a large-class high energy astrophysics space mission approved by ESA in the Cosmic Vision 2015-2025 Science Program. The X-IFU consists of a large array of transition edge sensor micro-calorimeters that operate at ~100 mK inside a sophisticated cryostat. To prevent molecular contamination and to minimize photon shot noise on the sensitive X-IFU cryogenic detector array, a set of thermal filters (THFs) operating at different temperatures are needed. Since contamination already occurs below 300 K, the outer and more exposed THF must be kept at a higher temperature. To meet the low energy effective area requirements, the THFs are to be made of a thin polyimide film (45 nm) coated in aluminum (30 nm) and supported by a metallic mesh. Due to the small thickness and the low thermal conductance of the material, the membranes are prone to developing a radial temperature gradient due to radiative coupling with the environment. Considering the fragility of the membrane and the high reflectivity in IR energy domain, temperature measurements are difficult. In this work, a parametric numerical study is performed to retrieve the radial temperature profile of the larger and outer THF of the Athena X-IFU using a Finite Element Model approach. The effects on the radial temperature profile of different design parameters and boundary conditions are considered: (i) the mesh design and material, (ii) the plating material, (iii) the addition of a thick Y-cross applied over the mesh, (iv) an active heating heat flux injected on the center and (v) a Joule heating of the mesh. The outcomes of this study have guided the choice of the baseline strategy for the heating of the Athena X-IFU THFs, fulfilling the stringent thermal specifications of the instrument.

A JWST Survey of the Supernova Remnant Cassiopeia A

We present initial results from a James Webb Space Telescope (JWST) survey of the youngest Galactic core-collapse supernova remnant, Cassiopeia A (Cas A), made up of NIRCam and MIRI imaging mosaics that map emission from the main shell, interior, and surrounding circumstellar/interstellar material (CSM/ISM). We also present four exploratory positions of MIRI Medium Resolution Spectrograph integral field unit spectroscopy that sample ejecta, CSM, and associated dust from representative shocked and unshocked regions. Surprising discoveries include (1) a weblike network of unshocked ejecta filaments resolved to ∼0.01 pc scales exhibiting an overall morphology consistent with turbulent mixing of cool, low-entropy matter from the progenitor’s oxygen layer with hot, high-entropy matter heated by neutrino interactions and radioactivity; (2) a thick sheet of dust-dominated emission from shocked CSM seen in projection toward the remnant’s interior pockmarked with small (∼1″) round holes formed by ≲0.″1 knots of high-velocity ejecta that have pierced through the CSM and driven expanding tangential shocks; and (3) dozens of light echoes with angular sizes between ∼0.″1 and 1′ reflecting previously unseen fine-scale structure in the ISM. NIRCam observations place new upper limits on infrared emission (≲20 nJy at 3 μm) from the neutron star in Cas A’s center and tightly constrain scenarios involving a possible fallback disk. These JWST survey data and initial findings help address unresolved questions about massive star explosions that have broad implications for the formation and evolution of stellar populations, the metal and dust enrichment of galaxies, and the origin of compact remnant objects.

Differential optical transfer function (dOTF) broad-spectrum wavefront sensing using integral field unit spectroscopy

Context. Detecting and characterizing Earth-like exoplanets is a critical scientific goal for the next generation of telescopes. However, current direct imaging instruments are hindered by evolving noncommon path aberrations (NCPAs), which lead to persistent speckles in the images. The differential optical transfer function (dOTF) is an image-based, noniterative, and model-independent wavefront sensor that combines differential images to estimate the complex field of the pupil. Aims. Given the objective of spectrally characterizing exoplanets to discern their composition and potentially detect biosignatures, we aim to explore the integration of the dOTF sensing method with an integral field unit (IFU) spectrograph. An IFU spectrograph generates a spectral data cube that contains diverse spectral information within a single dataset. Combining these two concepts is expected to improve the efficiency with which NCPAs can be spectrally measured and characterized. Methods. This Letter presents an implementation strategy for integrating dOTF and IFU spectroscopy data, enabling estimations of the electric field at various wavelengths simultaneously. Results. This method is specifically optimized to provide the most effective combination with minimal hardware requirements. It involves the use of multiple simultaneous deformable mirror actuator displacements in conjunction with an adapted Lyot stop employing a circular variable filter. Conclusions. The dOTF wavefront sensor coupled with an IFU spectrograph promises to be rapid and efficient, capable of measuring NCPAs across the entire spectrum provided by the spectrograph. Because the combination of dOTF and IFU spectroscopy is immediately applicable, it is of potential interest for various present-day on-sky instruments, as well as future IFU-based instruments coupled to the next generation of extremely large telescopes (ELTs).

BUDDI-MaNGA

The many unique properties of galaxies are shaped by physical processes that affect different components of the galaxy – such as their bulges and discs – in different ways, and they leave characteristic imprints on the light and spectra of these components. Disentangling these spectra reveals vital clues that can be traced back in time to understand how galaxies, and their components, form and evolve throughout their lifetimes. With BUDDI, we have decomposed the integral field unit (IFU) datacubes in SDSS-MaNGA DR17 into Sérsic bulge and exponential disc components and extracted clean bulge and disc spectra. BUDDI-MaNGA is the first large statistical sample of such decomposed spectra of 1452 galaxies covering morphologies from ellipticals to late-type spirals. We derive stellar masses of the individual components with spectral energy distribution (SED) fitting using BAGPIPES and estimate their mean mass-weighted stellar metallicities and stellar ages using PPXF. With this information, we reconstruct the mass assembly histories of the bulges and discs of 968 spiral galaxies (Sa-Sm types). Our results show a clear downsizing effect especially for the bulges, with more massive components assembling earlier and faster than the less massive ones. Additionally, we compare the stellar populations of the bulges and discs in these galaxies, and find that a majority of the bulges host more metal-rich and older stars than their disc counterparts. Nevertheless, we also find a non-negligible fraction of the spiral galaxy population in our sample contains bulges that are younger and more metal-enhanced than their discs. We interpret these results, taking into account how their formation histories and current stellar populations depend on stellar mass and morphology.

The first cut is the cheapest: optimizing Athena/X-IFU-like TES detectors resolution by filter truncation

The X-ray Integral Field Unit (X-IFU) instrument on the future ESA mission Athena X-ray Observatory is a cryogenic micro-calorimeter array of Transition Edge Sensor (TES) detectors designed to provide spatially-resolved high-resolution spectroscopy. The onboard reconstruction software provides energy, spatial location and arrival time of incoming X-ray photons hitting the detector. A new processing algorithm based on a truncation of the classical optimal filter and called 0-padding, has been recently proposed aiming to reduce the computational cost without compromising energy resolution. Initial tests with simple synthetic data displayed promising results. This study explores the slightly better performance of the 0-padding filter and assess its final application to real data. The goal is to examine the larger sensitivity to instrumental conditions that was previously observed during the analysis of the simulations. This 0-padding technique is thoroughly tested using more realistic simulations and real data acquired from NASA and NIST laboratories employing X-IFU-like TES detectors. Different fitting methods are applied to the data, and a comparative analysis is performed to assess the energy resolution values obtained from these fittings. The 0-padding filter achieves energy resolutions as good as those obtained with standard filters, even with those of larger lengths, across different line complexes and instrumental conditions. This method proves to be useful for energy reconstruction of X-ray photons detected by the TES detectors provided proper corrections for baseline drift and jitter effects are applied. The finding is highly promising especially for onboard processing, offering efficiency in computational resources and facilitating the analysis of sources with higher count rates at high resolution.

Measuring the dynamical length of galactic bars

ABSTRACT We define a physically motivated measure for galactic bar length, called the dynamical length. The dynamical length of the bar corresponds to the radial extent of the trapped orbits that are the backbone supporting the bar feature. We propose a direct observational technique well suited to integral field unit spectroscopy to measure it. Identifying these orbits and using the dynamical length is a more faithful tracer of the secular evolution and influence of the bar. We demonstrate the success of our observational technique for recovering the maximal bar-parenting orbit in a range of simulations, and to show its promise we perform its measurement on a real galaxy. We also study the difference between traditionally used ellipse fit approaches to determine bar length and the dynamical length proposed here in a wide range of bar-forming N-body simulations of a stellar disc and dark matter halo. We find that ellipse fitting may severely overestimate measurements of the bar length by a factor of 1.5–2.5 relative to the extent of the orbits that are trapped and actually comprise the bar. This bias leads to overestimates of both bar mass and the ratio of corotation radius to bar length, i.e. the bar speed, affecting inferences about the evolution of bars in the real Universe.

Nutrient Uptake and Quality of Sesame (Sesamum indicum L.) as Influenced by Sulphur and Boron

At the Agronomy Field Unit, ZARS, UAS, GKVK, Bengaluru, a field experiment was carried out in kharif 2017 to examine the impact of sulphur and boron on sesame yield and quality (Sesamum indicum L.). Twelve treatments were reproduced three times in the experiment, which was set up using a factorial RCBD design. The application of the recommended dose of fertilisers (RDF) with 30 kg sulphur and 5 kg borax per ha resulted in significantly higher seed yield (470.00 kg ha-1) and stalk yield (3126 kg ha-1) than the application of the recommended dose of fertilisers with 40 and 5, 40 and 2.5, 30 and 5 kg sulphur and borax per ha (461.56 and 2826.67, 455.13 and 2733.33, 445.67 and 2626.67 kg per ha, respectively). Increased nutrient uptake of nitrogen (40.23 kg ha-1) phosphorus (15.01 kg ha-1) potassium (45.23 kg ha-1) sulphur (13 kg ha-1) and boron (162.4 ppm) was primarily responsible for increased seed and stalk yield. The application of the recommended dose of fertilisers with 40 kg sulphur and 5 kg borax per ha resulted in higher seed protein (10.72%). This matched RDF + 40 kg sulphur + 2.5 kg borax (10.66%). RDF+30 kg sulphur + 5 kg borax per ha produced the highest C: B ratio (3.5).

Development of a near-infrared wide-field integral field unit by ultra-precision diamond cutting

Development of a near-infrared wide-field integral field unit by ultra-precision diamond cutting

Double, double, toil, and trouble

Context. Compact obscured nuclei (CONs) are an extremely obscured (NH2 &gt; 1025 cm−2) class of galaxy nuclei thought to exist in 20–40 per cent of nearby (ultra-)luminous infrared galaxies While they have been proposed to represent a key phase of the active galactic nucleus (AGN) feedback cycle, the nature of these CONs – what powers them, their dynamics, and their impact on the host galaxy – remains unknown. Aims. This work analyses the galaxy-scale optical properties of the local CON NGC 4418 (z = 0.00727). The key aims of the study are to understand the impact of nuclear outflows on the host galaxy and infer the power source of its CON. Through the mapping of the galaxy spectra and kinematics, we seek to identify new structures in NGC 4418 to ultimately reveal more about the CON’s history, its impact on the host, and, more generally, the role CONs play in galaxy evolution. Methods. We present new, targeted integral field unit observations of the galaxy with the Multi-Unit Spectroscopic Explorer (MUSE). For the first time, we mapped the ionised and neutral gas components of the galaxy, along with their dynamical structure, to reveal several previously unknown features of the galaxy. Results. We confirm the presence of a previously postulated, blueshifted outflow along the minor axis of NGC 4418. We find this outflow to be decelerating and, for the first time, show it to extend in both directions from the nucleus. We report the discovery of two further outflow structures: a redshifted southern outflow connected to a tail of ionised gas surrounding the galaxy and a blueshifted bubble to the north. In addition to these features, we find the [O III] emission reveals the presence of knots across the galaxy, which are consistent with regions of the galaxy that have been photoionised by an AGN. Conclusions. We identify several new features in NGC 4418, including a bubble structure, a reddened outflow, and [O III] knot structures throughout the galaxy. We additionally confirm the presence of a bilateral blueshifted outflow along the minor axis. Based on the properties of these features, we conclude that the CON in NGC 4418 is most likely powered by AGN activity.

The Science Performance of the Gemini High Resolution Optical Spectrograph

The Gemini High Resolution Optical Spectrograph (GHOST) is a fiber-fed spectrograph system on the Gemini South telescope that provides simultaneous wavelength coverage from 348 to 1061 nm, and is designed for optimal performance between 363 and 950 nm. It can observe up to two objects simultaneously in a 7.′5 diameter field of regard at R ≃ 56,000 or a single object at R ≃ 75,000. The spectral resolution modes are obtained by using integral field units to image slice a 1.″2 aperture by a factor of five in width using 19 fibers in the high resolution mode and by a factor of three in width using 7 fibers in the standard resolution mode. GHOST is equipped with hardware to allow for precision radial velocity measurements, expected to approach meters per second precision. Here, we describe the basic design and operational capabilities of GHOST, and proceed to derive and quantify the key aspects of its on-sky performance that are of most relevance to its science users.

JWST MIRI MRS Observations of T Cha: Discovery of a Spatially Resolved Disk Wind

Understanding when and how circumstellar disks disperse is crucial to constrain planet formation and migration. Thermal winds powered by high-energy stellar photons have long been theorized to drive disk dispersal. However, evidence for these winds is currently based only on small (∼3–6 km s−1) blueshifts in [Ne ii] 12.81 μm lines, which does not exclude MHD winds. We report JWST MIRI MRS spectro-imaging of T Cha, a disk with a large dust gap (∼30 au in radius) and blueshifted [Ne ii] emission. We detect four forbidden noble gas lines, [Ar ii], [Ar iii], [Ne ii], and [Ne iii], of which [Ar iii] is the first detection in any protoplanetary disk. We use line flux ratios to constrain the energy of the ionizing photons and find that argon is ionized by extreme ultraviolet, whereas neon is most likely ionized by X-rays. After performing continuum and point-spread function subtraction on the integral field unit cube, we discover a spatial extension in the [Ne ii] emission off the disk continuum emission. This is the first spatially resolved [Ne ii] disk wind emission. The mostly ionic spectrum of T Cha, in combination with the extended [Ne ii] emission, points to an evolved stage for any inner MHD wind and is consistent with the existence of an outer thermal wind ionized and driven by high-energy stellar photons. This work acts as a pathfinder for future observations aiming at investigating disk dispersal using JWST.

Undermassive Host Galaxies of Five z ∼ 6 Luminous Quasars Detected with JWST

We measure host galaxy stellar masses for a sample of five luminous quasars at z ∼ 5–7. Using JWST/NIRCam medium-band images of nearby point-spread function reference stars, we carefully subtract the contribution from the quasar light to place upper and lower limits on the flux of each host galaxy. We find that the members of our sample of quasar host galaxies have mass upper limits of 109.7–1010.8 M ⊙, significantly less than expected from their supermassive black hole (SMBH) masses and the local M BH–M * relation. We additionally obtain JWST/NIRSpec integral field unit spectra of three of our quasars to calculate black hole masses, which we find are consistent with those in the literature, and to search for the presence of bright but compact galaxies via a Balmer break, for which we do not find evidence. We discuss the potential effects of dust extinction on our measured fluxes and the impact of selection effects on high-redshift quasar samples. We conclude that the masses of the SMBHs relative to the host galaxy stellar masses have a much larger scatter than locally, large enough that these selection effects cannot be responsible. This result is reinforced by other studies. Finally, we explore the potential implications of these results on the picture of SMBH–galaxy coeval growth in the early Universe.