arXiv subjects

Nadia L. Zakamska

Publications and source records attributed to Nadia L. Zakamska.

At least 19 recordsLinked to original sources

arXiv2026

First Results from the JWST Early Release Science Program Q3D: AGN Photoionization and Shock Ionization in a Red Quasar at $z = 0.4$

Red quasars, often associated with powerful [O III] outflows on both galactic and circumgalactic scales, may play a pivotal role in galaxy evolution and black hole feedback. In this work, we explore the [Fe II] emission in one such quasar at redshift $z = 0.4352$, F2M J110648.32+480712.3, using the integral field unit (IFU) mode of the Near Infrared Spectrograph (NIRSpec) aboard the James Webb Space Telescope (JWST). Our observations reveal clumpy [Fe II] gas located to the south of the quasar. By comparing the kinematics of [Fe II] and [O III], we find that the clumpy [Fe II] gas in the southeast and southwest aligns with the outflow, exhibiting similar median velocities up to $v_{50} \sim 1200$ km/s and high velocity widths $W_{80} > 1000$ km/s. In contrast, the [Fe II] gas to the south shows kinematics inconsistent with the outflow, with $W_{80} \sim 500$ km/s, significantly smaller than the [O III] at the same location, suggesting that the [Fe II] may be confined within the host galaxy. Using standard emission-line diagnostic ratios, we map the ionization sources of the gas. According to the MAPPINGS III shock models for [Fe II]/Pa$β$, the regions to the southwest and southeast of the quasar are primarily photoionized. Conversely, the [Fe II] emission to the south is likely excited by shocks generated by the back-pressure of the outflow on the galaxy disk, a direct signature of the impact of the quasar on its host.

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arXiv2026

Blowing star formation away in AGN hosts (BAH) -- V: The Feeding-Feedback Cycle in local AGNs as revealed by their stellar populations

We present a spatially resolved analysis of the stellar populations in the inner kiloparsec of NGC 3884, 3C 293, and CGCG 012-070. Using near-infrared spectroscopy, we reconstruct their star formation histories (SFHs) by comparing the M13, XSL, and FSPS stellar population synthesis models. The stellar light is dominated by intermediate-age to old populations (t >= 1 Gyr) with super-solar metallicities (Z >= 1 Z_sun). All models clearly indicate recent star formation (rejuvenation) in these AGN hosts, with young to intermediate-age populations contributing significantly in the nuclear regions. The SFHs from M13 and XSL broadly agree in showing coexisting old and young components, whereas FSPS favours a larger fraction of very young (t < 50 Myr) stars. Moreover, XSL- and FSPS-based SFHs are generally more irregular and "bumpy," while M13 yields smoother, more continuous SFHs. In NGC 3884 and 3C 293, stars with 0.2 < t <= 0.7 Gyr form a ring-like structure around the nucleus. The nuclear spectra further require non-stellar components: a featureless power-law continuum (FC) and hot dust emission (HD). In 3C 293, the FC component appears in two spatially separated regions, possibly indicating a dual active galactic nucleus, though a heavily reddened starburst origin for the secondary component cannot be excluded. Nearly all fits show a central drop in stellar metallicity, consistent with inflow of metal-poor gas that fuels recent accretion and AGN activity. Radial profiles show that HD and FC contributions decrease with radius, while younger stellar populations become more prominent outward. Together, these results support a feeding-feedback scenario in which gas inflows trigger circumnuclear star formation and, via stellar mass loss, help sustain ongoing AGN activity. .

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arXiv2026

Varstrometry for Off-nucleus and Dual Subkiloparsec AGN (VODKA): Three Quadruply Lensed Quasars at Cosmic Noon in HST and JWST

We present results from imaging observations of three quadruply lensed quasars by Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) at redshifts $z = 2.550$, 2.975, and 1.500. We model our targets assuming a singular isothermal ellipsoid mass profile and an elliptical SÃ\c{opyright}rsic profile for the lensing galaxies, and reconstruct the geometric configuration of each system with measured Einstein radii of 0.44$'$, 0.58$'$, and 0.49$'$. While no spectroscopic measurements are available for the lenses, we constrain the redshift of each lens to $0.5 < z < 1.2$, $1.0 < z < 1.5$, and $0.4 < z < 0.9$. For all three lenses, the best-fit light model yield a typical de Vaucouleurs $n_{\rm S\acute{e}rsic} \sim 4$ profile and an effective radius $R_e$ around $\sim 1.5 - 3.5$ kpc. We accordingly classify the three lenses as early-type galaxies at an intermediate to high redshift, a common type for strong lensing galaxies. Compared to other known quadruple lenses, the lensing galaxies in this work are at the lower end of the distribution of Einstein radii and upper end of the distribution of the lens redshifts. They represent an interesting quadrant of subarcsecond-separation lenses in the population of single-galaxy strong lensing which have been largely unexplored yet and will be great targets of interest in upcoming high-resolution lensing surveys.

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arXiv2026

Kinematic Stratification in Extremely Red Quasars Revealed by JWST

We analyze the spectra of the central nuclei of extremely red quasars (ERQs) observed as part of the JWST ERS Q3D program. We focus on the complex kinematic structures of the prominent rest-frame optical emission lines. Our modeling allows us to deblend the lines and separate the emission into distinct kinematic components that imply velocity- and density-stratified gas structures on a range of physical scales within the ERQs. Supplementing the JWST data with archival data, we analyze the spectral energy distributions (SEDs) of the ERQs and find they are consistent with a significantly dust-obscured central source with a small amount of relatively-unobscured UV/optical flux that is scattered into our line-of-sight. While the kinematics of the UV and optical emission lines largely agree, the UV lines are dominated by scattered light. In contrast, the optical emission-line ratios indicate a combination of scattered and obscured emission. Our analysis focuses on one ERQ, J0834, because its distinct spectroscopic features allow the emission to be easily decomposed into separate kinematic components.

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arXiv2026

Under Pressure: UV Emission Line Ratios as Barometers of AGN Feedback Mechanisms

Feedback from active galactic nuclei (AGN) is widely acknowledged to regulate the growth of massive galaxies, though its driving mechanisms are debated. Prevailing theories suggest that AGN-driven outflows are driven either by radiation pressure acting directly on the dusty interstellar medium (ISM) or by hot winds entraining cooler ISM gas, but the relative contribution of each mechanism remains uncertain. By combining optical emission line measurements with highly ionized UV emission lines, it is possible to constrain whether the pressure source applied to ionized clouds is primarily radiation or primarily hydrodynamic, and thus constrain the dominant driver. This study presents the first multi-object analysis of far-ultraviolet (FUV) spectra from galactic-scale AGN-driven outflows in obscured quasars, based on Cosmic Origins Spectrograph observations of five low-redshift targets. By comparing narrow-line region UV emission line ratios to theoretical models that vary the importance of the two pressure sources, we find three out of five targets fall within the radiation pressure-dominated regime. A fourth target exhibits intermediate emission-line ratios that suggest radiation pressure and pressure from a hot wind are both dynamically important. Finally, the lowest-luminosity object in our sample may have a dynamically important hot wind component, but non-detections prevent a clear conclusion in this case. These results suggest radiation pressure dominates circum-nuclear narrow-line region cloud dynamics, but pressure from a hot wind also plays a role in some cases. This is consistent with AGN feedback scenarios mediated by radiation pressure or a short-lived hot wind phase that dissipates after initially accelerating outflows.

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arXiv2026

Presaging Doppler beaming discoveries of double white dwarfs during the Rubin LSST era

Double white dwarfs (DWDs) are by far the most common compact binaries in the Milky Way, are important low-frequency gravitational-wave sources, and in some cases merge to become Type Ia supernovae. So far, no DWD has been identified solely through relativistic Doppler beaming, even though the beaming amplitude directly relates to the radial velocity semi-amplitude. In this work, we initiate a comprehensive binary population synthesis using SeBa and incorporate the resulting binaries into a tripartite Galaxy model. Our proof-of-concept simulations demonstrate that the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) can reliably recover relatively bright ($r \lesssim20~$mag) unequal-mass binaries in compact orbits with P $\approx$ 10-600 minutes with moderate to high inclinations. We find that LSST can detect at least 287 short-period DWDs, of which 47 are LISA-detectable gravitational wave sources. LSST lightcurves allow us to readily determine the period and fully characterize the orbit, in contrast with the challenges of orbit determination for DWDs in spectroscopic searches. The formation of unequal mass, short-period DWDs strongly depends on the assumptions regarding the mass-transfer phases during binary population synthesis, and the total number and characteristics of Doppler-beamed DWD systems observed in LSST will provide new tests of models of stellar binary evolution. Here, we lay the foundation for the comprehensive integration of synthetic Galactic binary population into realistic LSST survey simulations, thereby enabling quantitative forecasts of the number and characteristics of any binary sub-population during the LSST era.

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arXiv2025

ASASSN-24fw: Candidate circumplanetary disk occultation of a main-sequence star

Dusty disks around planetary and substellar companions in outer reaches of exo-planetary systems can be detected as long-lasting occultations, provided the observer is close to the secondary's orbital plane. Here we report optical spectroscopy with KOSMOS (APO), MagE (Magellan) and GHOST (Gemini-S) of ASASSN-24fw (Gaia 07:05:18.97+06:12:19.4), a 4-magnitude dimming event of a main-sequence star which lasted 8.5 months. We discover multiple low-ionization metal emission lines with velocity dispersion $\lesssim 10$ km/s blue-shifted by 27 km/s with respect to the star, as well as kinematically complex Na D absorption. If associated with the occulter, these detections suggest that the occulter is gas-rich. Further, we detect blue-shifted and broad ($\sim 200$ km/s) H$α$ line, which likely originates in the inner circumstellar disk. We confirm the previously reported occultations in 1981 and 1937 seen in historic data, yielding a semi-major axis of the occulter's orbital motion around the star of 14 AU. If the occulter is a circumsecondary disk filling 30-100% of the Hill radius, we estimate the minimum mass of the secondary to be a few Jupiter masses and a disk mass of 1% of the mass of the Moon. Given the age of the star ($>2$ Gyr), the disk is unlikely to be a survivor of the planet formation stage and may be a result of a planetary collision. If Na D absorption and/or metal emission lines originate in the disk, the observations presented here are the first discovery of a circumsecondary disk wind or rotation.

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arXiv2025

Blowing star formation away in AGN Hosts (BAH) -- IV: Feeding and feedback in 3C 293 observed with JWST NIRSpec

We use JWST/NIRSpec observations of the radio galaxy 3C 293 to map the emission, extinction, and kinematics of hot molecular and ionized gas, as well as stellar kinematics, within the inner ~ 2 kpc. The stellar velocity field is well described by a rotating disk model, with its kinematical center offset by ~ 0.5 arcsec from the continuum peak. The hot molecular gas is traced by the H$_2$2.12$μ$m emission line, and the ionized gas by [Fe II]1.64$μ$m and Pa$α$. The gas presents three main kinematic components: a rotating disk seen as a narrow component ($σ$ ~ 100 kms$^{-1}$); a blueshifted broad outflow ($σ$ ~ 250 kms$^{-1}$); and a fast ionized outflow as a very broad component ($σ$ ~ 640 kms$^{-1}$). Extinction maps reveal high A$_V$ values, up to ~ 35, spatially coincident with dust lanes seen in optical images. In addition to the disk and outflows components, inflows along the dust lanes are detected in H$_2$ gas, with a mass inflow rate of $\dot{M}_{in}$ ~ 4 x 10$^{-4}$ M$_{\odot}$ yr$^{-1}$, which is lower than the AGN accretion rate. For the outflows, we derive peak mass-outflow rates of 0.08 $\pm$ 0.02 M$_{\odot}$yr$^{-1}$ (molecular) and 6.5 $\pm$ 1.7 M$_{\odot}$yr$^{-1}$ (ionized). The outflow, driven by the radio jet, has a kinetic power of 5.7% of the jet power - enough to suppress star formation. Our results highlight 3C 293's turbulent post-merger history and JWST's unique capability to probe dust-obscured AGN.

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arXiv2025

Searching for Ultra-light Dark Matter in Spatial Correlations of White Dwarf Structure

If dark matter is ultra-light and has certain Standard Model interactions, it can change the mass-radius relation of white dwarf stars. The coherence length of ultra-light dark matter imparts spatial correlations in deviations from the canonical mass-radius relation, and thus white dwarfs can be used to reconstruct the coherence length, or equivalently the particle mass, of the dark matter field. We simulate the observability of such spatial correlations accounting for realistic complications like variable hydrogen envelope thickness, dust, binaries, measurement noise, and distance uncertainties in DA white dwarfs. Using a machine learning approach on simulated data, we measure the dark matter field coherence length and find that large deviations from the mass-radius relation ($\sim10\%$ change in radius) are needed to produce an observable signal given realistic noise sources. We apply our spatial correlation measurement routine to the SDSS catalog of 10,207 DA white dwarfs. We detect a positive spatial correlation among white dwarfs at separations corresponding to a coherence length of $300\pm50$ pc, with an average Z-score of 85 for white dwarfs separated by less than this coherence length. We conclude that this signal is due to observational bias. The signal can be explained by an offset between measurements and theory for nearby cool white dwarfs, and the presence of few, low-temperature white dwarfs with noisy measurements at further distances. With future improvements in white dwarf models and measurement techniques, particularly for cool white dwarfs, this method can provide interesting constraints on ultra-light dark matter models.

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arXiv2025

Blowing Star Formation Away in AGN Hosts (BAH) -- III. Serendipitous discovery of a $z\sim2.9$ star-forming galaxy lensed by the galactic bulge of CGCG 012-070 using JWST NIRSpec

We report the detection of a gravitationally lensed galaxy by the nearby spiral galaxy CGCG 012-070 ($z = 0.048$) using Integral Field Unit (IFU) observations with the Near-Infrared Spectrograph (NIRSpec) instrument on board the James Webb Space Telescope (JWST). The lensed galaxy is identified through the flux distributions of emission lines in the rest-frame optical, consistent with a source located at a redshift of $z\sim2.89$. The system is detected in [O III]$λ\lambda4959,5007$, H$β$, and H$α$ emission lines, exhibiting line ratios typical of a star-forming galaxy. The emission-line flux distributions reveal three distinct components, which are modeled using an elliptical power-law (EPL) mass profile for the lens galaxy. This model provides a good characterization of the source and reveals a disturbed star-forming morphology consistent with those of galaxies at cosmic noon. This serendipitous discovery of a rare low-redshift strong lens highlights the critical role of IFU observations in expanding the lens census and advancing our understanding of galaxy mass profiles and evolution.

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arXiv2025

Double White Dwarf Binaries in SDSS-V DR19 : A catalog of DA white dwarf binaries and constraints on the binary population

The fifth-generation Sloan Digital Sky Survey (SDSS-V) includes the first large-scale spectroscopic survey of white dwarfs (WDs) in the era of Gaia parallaxes. SDSS-V collects multiple exposures per target, making it ideal for binary detection. We present a search for hydrogen atmosphere (DA) double white dwarf (DWD) binaries in this rich dataset. We quantify radial velocity variations between sub-exposures to identify binary candidates, and also measure the orbital period for a subset of DWD binary candidates. We find 63 DWD binary candidates, of which 43 are new discoveries, and we provide tentative periods for 10 binary systems. Using these measurements, we place constraints on the binary fraction of the Galactic WD population with $< 0.4$ AU separations $f_{\mathrm{bin,0.4}} = 9\%$, and the power-law index of the initial separation distribution $α= -0.62$. Using the simulated binary population, we estimate that $\leq 10$ super-Chandrasekhar binaries that merge within a Hubble time are expected in our sample. We predict that $\leq 5$ systems in our sample should be detectable via gravitational waves by LISA (Laser Interferometer Space Antenna), one of which has already been identified as a LISA verification source. We also estimate a total of about 10,000 - 20,000 LISA-detectable DWD binaries in the galaxy. Our catalog of WD+WD binary candidates in SDSS-V is now public, and promises to uncover a large number of exciting DWD systems.

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arXiv2025

Resolution-Corrected White Dwarf Gravitational Redshifts Validate SDSS-V Wavelength Calibration and Enable Accurate Mass-Radius Tests

Leveraging the large sample size of low-resolution spectroscopic surveys to constrain white dwarf stellar structure requires an accurate understanding of the shapes of hydrogen absorption lines, which are pressure broadened by the Stark effect. Using data from both the Sloan Digital Sky Survey and the Type Ia Supernova Progenitor Survey, we show that substantial biases (5-15 km/s) exist in radial velocity measurements made from observations at low spectral resolution relative to similar measurements from high-resolution spectra. Our results indicate that the physics of line formation in high-density plasmas, especially in the wings of the lines, are not fully accounted for in state-of-the-art white dwarf model atmospheres. We provide corrections to account for these resolution-induced redshifts in a way that is independent of an assumed mass-radius relation, and we demonstrate that statistical measurements of gravitational redshift with these corrections yield improved agreement with theoretical mass-radius relations. Our results provide a set of best practices for white dwarf radial velocity measurements from low-resolution spectroscopy, including those from the Sloan Digital Sky Survey, the Dark Energy Spectroscopic Instrument, the 4-meter Multi-Object Spectroscopic Telescope, and the Wide-Field Multiplexed Spectroscopic Facility.

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arXiv2025

Luminous Mid-IR Selected Obscured Quasars at Cosmic Noon in SDSS Stripe82 II: Spectroscopic Diversity and Broad H$α$ Emissions

We present a multiwavelength spectroscopic survey of 23 luminous mid-infrared-selected Type-2 quasars at redshifts z = 0.88 to 3.49. The targets were selected in the SDSS Stripe 82 field based on their bright WISE W4 detections (flux > 5 mJy) and extremely faint or red optical counterparts (e.g., r > 23 or r - W4 > 8.4), designed to identify heavily obscured quasars. Deep near-infrared (Gemini/GNIRS) and optical (Keck/LRIS and KCWI) spectroscopy confirm 23 out of 24 candidates as Type-2 quasars in this redshift range, including 12 objects at z > 2. The spectra exhibit strong rest-frame UV and optical emission lines (Ly-alpha, C IV, [O III], H-alpha) with a wide range of line widths, indicating significant spectral diversity. Approximately one-third of the sample (8 of 23) shows broad H-alpha emission (FWHM > 2000 km/s) despite their Type-2 classification, while the rest have only narrow lines (FWHM < 2000 km/s) characteristic of classical obscured quasars. Notably, these broad-line Type-2 quasars share similar spectral energy distributions with the JWST-discovered "little red dot" (LRD) AGNs, suggesting that our sample could be lower-redshift analogues of the heavily obscured broad-line AGNs uncovered by JWST. We also find that the [O III] 5007 angstrom emission is relatively weak for their high bolometric luminosities, deviating from trends seen in lower-redshift Type-2 QSOs. A new composite spectrum for Type-2 QSOs is built using our sample. Overall, our results demonstrate that mid-IR selection efficiently uncovers a diverse population of obscured quasars and that spectroscopic follow-up is crucial for revealing their true nature. This study provides new insights into heavily obscured SMBH growth at cosmic noon and bridges the gap to the obscured AGN populations now being revealed by JWST.

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arXiv2025

A Large Catalog of DA White Dwarf Characteristics Using SDSS and Gaia Observations

We present a catalog of 8545 and 19,257 unique DA white dwarfs observed in SDSS Data Release 19 and previous SDSS data releases, respectively. This is the largest catalog of both spectroscopic and photometric measurements of DA white dwarfs available to date, and we make this catalog and all code used to create it publicly available. We measure the apparent radial velocity, spectroscopic effective temperature and surface gravity, and photometric effective temperature and radius for all objects in our catalog. We validate our measurements against other published white dwarf catalogs. For apparent radial velocities, surface gravities, and effective temperatures measured from spectra with signal-to-noise ratios $>50$, our measurements agree with published SDSS white dwarf catalogs to within 7.5 km/s, 0.060 dex, and $2.4\%$, respectively. For radii and effective temperatures measured with Gaia photometry, our measurements agree with other published Gaia datasets to within $0.0005$ $R_\odot$ and $3\%$, respectively. We use this catalog to investigate systematic discrepancies between white dwarfs observed in SDSS-V and previous generations of SDSS. For objects observed in both SDSS-V and previous generations, we uncover systematic differences between measured spectroscopic parameters depending on which set of survey data is used. On average, the measured apparent radial velocity of a DA white dwarf is $11.5$ km/s larger and the surface gravity is $0.015$ dex smaller when a white dwarf's spectroscopic parameters are measured using SDSS-V data compared to using data from previous generations of SDSS. These differences may be due to changes in the wavelength solution across survey generations.

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arXiv2025

Double White Dwarf Binaries in SDSS-V DR19 : The discovery of a rare DA+DQ white dwarf binary with 31 hour orbital period

Binaries of two white dwarfs (WDs) are an important class of astrophysical objects that are theorized to lead to Type Ia supernovae and are also used to gain insight into complex processes involved in stellar binary evolution. We report the discovery of SDSS~J090618.44+022311.6, a rare post-common envelope binary of a hydrogen atmospheric DA WD and a DQ WD which shows carbon absorption features, and is only the fourth such binary known. We combine the available spectroscopic, photometric, and radial velocity data to provide a self-consistent model for the binary and discuss its history as a binary DA+DQ. The system has a period of 31.17 hours with masses of 0.42 M$_{\odot}$ for DA WD and 0.49 M$_{\odot}$ for DQ WD. The corresponding cooling ages point to an Algol type of evolution with the lower mass star evolving into a DA WD first and later the massive DQ WD is formed. The system has a merger timescale of 450 Gyrs and will lead to the formation of a massive WD. With this, the number of known DA+DQ WD binaries has increased to four, and we find that their stellar properties all lie in the same range. Detailed study of more such systems is vital to understand common processes involved in the formation of this rare class of binaries and give insights towards the broader picture of WD spectral evolution.

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arXiv2025

Discovery of a Proto-White Dwarf with a Massive Unseen Companion

We report the discovery of SDSS~J022932.28+713002.7, a nascent extremely low-mass (ELM) white dwarf (WD) orbiting a massive ($> 1\,M_\odot$ at 2$σ$ confidence) companion with a period of 36 hours. We use a combination of spectroscopy, including data from the ongoing SDSS-V survey, and photometry to measure the stellar parameters for the primary pre-ELM white dwarf. %Because of the degeneracy between inclination, mass of the companion and lack of constraints on the inclination, mass of the companion is uncertain. The lightcurve of the primary WD exhibits ellipsoidal variation, which we combine with radial velocity data and $\tt{PHOEBE}$ binary simulations to estimate the mass of the invisible companion. We find that the primary WD has mass $M_1$ = $0.18^{+0.02}_{-0.02}$ M$_\odot$ and the unseen secondary has mass $M_2$ = $1.19^{+0.21}_{-0.14}$ M$_\odot$. The mass of the companion suggests that it is most likely a near-Chandrasekhar mass white dwarf or a neutron star. It is likely that the system recently went through a Roche lobe overflow from the visible primary onto the invisible secondary. The dynamical configuration of the binary is consistent with the theoretical evolutionary tracks for such objects, and the primary is currently in its contraction phase. The measured orbital period puts this system on a stable evolutionary path which, within a few Gyrs, will lead to a contracted ELM white dwarf orbiting a massive compact companion.

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arXiv2025

Varstrometry for Off-nucleus and Dual sub-Kpc AGN (VODKA): Long-slit optical spectroscopic follow-up with Gemini/GMOS and HST/STIS

High spatial and spectral resolution observations are essential for identifying sub-arcsecond dual and lensed quasars and confirming their redshifts. We present Gemini/GMOS and HST/STIS optical spectra for 27 dual quasar candidates selected based on their variability-induced astrometric noise or double detections in Gaia (the VODKA project). From this follow-up, we spectroscopically identify 11 star superpositions and 7 dual/lensed quasars. Among the remaining targets, 2 are likely dual/lensed quasars based on additional radio imaging, while the rest are quasars with unknown companions. Without prior photometric or spectroscopic selection, we find the star contamination rate to be 41-67%, while the dual/lensed quasar fraction is $\gtrsim$ 26% in the follow-up VODKA sample. However, when combined with existing unresolved spectra and spatially-resolved two-band color cuts, the dual/lensed quasar fraction can be increased to $\gtrsim$ 67%. Our study highlights the need for high-quality spectral data, including a signal-to-noise ratio of at least 20, spatial resolution that is at least twice finer than the source separation, and a spectral resolution of $R \gtrsim 1000$, in order to separate close sources, exclude stellar superpositions, and reliably identify dual quasars.

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arXiv2025

JWST IFU observations uncover host galaxy continua in extremely red and obscured quasars

Uncovering bright quasars' host galaxies at cosmic noon is challenging because of the high contrast between the quasar and its host and redshifted light, making them primarily visible in the infrared. We present JWST NIRSpec integral field unit (IFU) observations of six extremely red quasars (ERQs) at $z=2.4-2.9$ and two dust-obscured quasars at lower redshifts. Using image decomposition across the spectral range, we successfully separate quasar and host galaxy continuum emission, model host morphologies, and extract spectra. The ERQs and obscured quasars have compact host galaxies with half-light radii of 1.4$-$2.9 kpc and stellar masses of 10$^{10.6-10.9}$ $M_{\odot}$. Their stellar masses are consistent with the average stellar mass of quasar hosts as expected from abundance matching and clustering analysis. Most of the quasars in our sample exhibit significant spatial offsets (0.4$-$1.3 kpc) between the quasar and host galaxy, potentially caused by post-merger dynamics or non-uniform dust obscuration. The ERQs reside 0.5$-$2 dex above the local black hole-stellar mass relation, similar to other heavily obscured populations such as HotDOGs, optically selected quasars at cosmic noon, and high-redshift SMBH candidates identified with JWST. However, this "over-massive" feature might be attributed to selection bias. Compared to HST-based studies, our JWST measurements reveal more compact host galaxies, smaller Sersic indices, and lower stellar masses, likely because of improved resolution, more accurate modeling, and minimal line contamination. These findings highlight the unique capabilities of JWST IFU in revealing quasar host galaxy properties and potential evolutionary stages of obscured quasars at cosmic noon.

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