arXiv subjects

Margaret Lazzarini

Publications and source records attributed to Margaret Lazzarini.

At least 19 recordsLinked to original sources

arXiv2026

Optical Spectroscopy of a Candidate O-Star X-ray Binary in M33

We present new observations of a candidate O-type donor star in a high mass X-ray binary (HMXB) in M33. The candidate donor star is spatially coincident with a hard X-ray point source. The star's optical magnitude and colors are consistent with what is expected for a massive star. The four band optical/UV spectral energy distribution (SED) of the donor star is well fit by an O-giant model with an effective temperature of $\sim$43 kK, mass of 75$_{+9}^{-0.3}$ $M_{\odot}$, and surface gravity of log(g) of $\sim$3.8. We present four epochs of optical spectroscopy of the donor star taken with the Keck/DEIMOS spectrograph over the course of approximately one year. Features in the star's spectrum are consistent with an O-type star. The star's spectrum exhibits a strong H$α$ emission line during all epochs of observation with a variable line profile. We measure the star's radial velocity for each epoch, which we use to fit for a systemic velocity. We find that the systemic velocity is offset from the local gas velocity from HI measurements, suggesting that the system has a peculiar velocity relative to the local gas. We observe a radial velocity shift in the He I absorption lines that is consistent with motion within a binary system.

astro-ph.HE↗

arXiv2026

The Panchromatic Hubble Andromeda Southern Treasury (PHAST). II. The Spatially Resolved Recent Star Formation History in M31

We use Hubble Space Telescope optical imaging from the Panchromatic Hubble Andromeda Southern Treasury (PHAST) to measure the spatially resolved recent star formation history (SFH) across the southern disk of M31. We fit color-magnitude diagrams (CMDs) of over 6500 individual 0.01 kpc$^2$ regions to measure SFHs over the last $\sim$500 Myr. The resulting maps show coherent structure that traces the ringed morphology of the disk. We find a clear global decline in the recent SFR, with a pronounced drop in the last $\sim$40 Myr that is most evident in the region closest to M32. Combining PHAST and PHAT measurements, we now cover two thirds of M31's star-forming disk with homogeneous SFHs, yielding the highest-resolution spatially resolved SFHs of M31. Inside the joint footprint, we measure mean SFRs of $0.445 \pm0.006$ M$_\odot$ yr$^{-1}$ over the last 100 Myr and $0.285 \pm 0.014$ M$_\odot$ yr$^{-1}$ over the last 20 Myr, implying total disk SFRs of $\sim$0.67 and $\sim$0.43 M$_\odot$ yr$^{-1}$, respectively. The observed decline is interpreted as the late stage of a multi-Gyr wind-down from a previously more active state. Because recent star formation in M31 is concentrated primarily in the rings, the global decline is driven mainly by decreasing activity within those features. We also compare the CMD-based SFR surface densities to those inferred from FUV+24 $μ$m prescriptions and find that the FUV-based calibration underestimates the CMD-based 100 Myr average by a factor of $\sim$2.1. However, the PHAST SFHs produce a synthetic GALEX FUV image that agrees well with observations, indicating that the CMD-derived SFHs provide an accurate description of recent star formation. The mismatch with the FUV+24 $μ$m estimates underscores that tracers implicitly averaged over $\sim$100 Myr are not reliable when the recent SFR is evolving.

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arXiv2025

A First-look at Spatially-resolved Infrared Supernova Remnants in M33 with JWST

We present the first spatially-resolved infrared images of supernova remnants (SNRs) in M33 with the unprecedented sensitivity and resolution of JWST. We analyze 40 SNRs in four JWST fields: two covering central and southern M33 with separate NIRCam (F335M, F444W) and MIRI (F560W, F2100W) observations, one $\sim$5 kpc-long radial strip observed with MIRI F770W, and one covering the giant HII region NGC 604 with multiple NIRCam and MIRI broad/narrowband filters. Of the 21 SNRs in the MIRI (F560W+F2100W) field, we found three clear detections (i.e., identical infrared and H$α$ morphologies), and six partial-detections, implying a detection fraction of 43\% in these bands. One of the SNRs in this field, L10-080, is a potential candidate for having freshly-formed ejecta dust, based on its size and centrally-concentrated 21 $μ$m emission. In contrast, only one SNR (out of 16) is detectable in the NIRCam F335M+F444W field. Two SNRs near NGC 604 have strong evidence of molecular (H$_2$) emission at 4.7 $μ$m, making them the farthest known SNRs with visible molecular shocks. Five SNRs have F770W observations, with the smaller younger objects showing tentative signs of emission, while the older, larger ones have voids. Multi-wavelength data indicate that the clearly-detected SNRs are also among the smallest, brightest at other wavelengths (H$α$, radio and X-ray), have the broadest line widths (H$α$ FWHM$\sim$250-350 km/s), and the densest environments. No correlation between the JWST-detectability and local star-formation history of the SNRs is apparent.

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arXiv2024

An Empirical Framework Characterizing the Metallicity and Star-Formation History Dependence of X-ray Binary Population Formation and Emission in Galaxies

We present a new empirical framework modeling the metallicity and star-formation history (SFH) dependence of X-ray luminous ($L > 10^{36}$ ergs s$^{-1}$) point-source population luminosity functions (XLFs) in normal galaxies. We expect the X-ray point-source populations are dominated by X-ray binaries (XRBs), with contributions from supernova remnants near the low luminosity end of our observations. Our framework is calibrated using the collective statistical power of 3,731 X-ray detected point-sources within 88 Chandra-observed galaxies at $D <$ 40 Mpc that span broad ranges of metallicity ($Z \approx$ 0.03-2 $Z_\odot$), SFH, and morphology (dwarf irregulars, late-types, and early-types). Our best-fitting models indicate that the XLF normalization per unit stellar mass declines by $\approx$2-3 dex from 10 Myr to 10 Gyr, with a slower age decline for low-metallicity populations. The shape of the XLF for luminous X-ray sources ($L < 10^{38}$ ergs s$^{-1}$) significantly steepens with increasing age and metallicity, while the lower-luminosity XLF appears to flatten with increasing age. Integration of our models provide predictions for X-ray scaling relations that agree very well with past results presented in the literature, including, e.g., the $L_{\rm X}$-SFR-$Z$ relation for high-mass XRBs (HMXBs) in young stellar populations as well as the $L_{\rm X}/M_\star$ ratio observed in early-type galaxies that harbor old populations of low-mass XRBs (LMXBs). The model framework and data sets presented in this paper further provide unique benchmarks that can be used for calibrating binary population synthesis models.

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arXiv2024

A NuSTAR Census of the X-ray Binary Population of the M31 Disk

Using hard (E>10 keV) X-ray observations with NuSTAR, we are able to differentiate between accretion states, and thus compact object types, of neutron stars and black holes in X-ray binaries (XRBs) in M31, our nearest Milky Way-type neighbor. Using ten moderate-depth (20-50 ks) observations of the disk of M31 covering a total of ~0.45 deg$^{2}$, we detect 20 sources at 2$σ$ in the 4-25 keV band pass, 14 of which we consider to be XRB candidates. This complements an existing deeper (100-400 ks) survey covering ~0.2 deg$^{2}$ of the bulge and the northeastern disk. We make tentative classifications of 9 of these sources with the use of diagnostic color-intensity and color-color diagrams, which separate sources into various neutron star and black hole regimes, identifying 3 black holes and 6 neutron stars. In addition, we create X-ray luminosity functions for both the full (4-25 keV) and hard (12-25 keV) band, as well as sub-populations of the full band based on compact object type and association with globular clusters. Our best fit globular cluster XLF is shallower than the field XLF, and preliminary BH and NS XLFs suggest a difference in shape based on compact object type. We find that the cumulative disk XLFs in the full and hard band are best fit by power laws with indices of 1.32 and 1.28 respectively. This is consistent with models of the Milky Way XLF from Grimm et al. (2002), Voss & Ajello (2010), and Doroshenko et al. (2014).

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arXiv2023

Monitoring the X-ray Variability of Bright X-ray Sources in M33

We present a new five-epoch Chandra X-ray Observatory monitoring survey of the nearby spiral galaxy M33 which probes X-ray variability with time sampling between two weeks and four months. We characterize the X-ray variability of 55 bright point sources outside of the nucleus, many of which are expected to be high-mass X-ray binaries (HMXBs). We detect eight new candidate transients not detected in previous X-ray catalogs of M33 and discuss their possible nature. The final catalog includes 26 known HMXB candidates identified in the literature. We extend the baseline of the X-ray light curves up to 21 years by including archival X-ray observations of these sources. We compare the detection and non-detection epochs of the sources to suites of simulated source duty cycles and infer that most of our detected sources have duty cycles > 30%. We find only four sources whose detection patterns are consistent with having duty cycles below 30%. This large fraction of sources with high duty cycles is unexpected for a population of HMXBs, thus more frequent X-ray monitoring will likely reveal many more low duty cycle HMXBs in M33.

astro-ph.HE↗

arXiv2023

The High Energy X-ray Probe: Resolved X-ray Populations in Extragalactic Environments

We construct simulated galaxy data sets based on the High Energy X-ray Probe (HEX-P) mission concept to demonstrate the significant advances in galaxy science that will be yielded by the HEX-P observatory. The combination of high spatial resolution imaging ($<$20 arcsec FWHM), broad spectral coverage (0.2-80 keV), and sensitivity superior to current facilities (e.g., XMM-Newton and NuSTAR) will enable HEX-P to detect hard (4-25 keV) X-ray emission from resolved point-source populations within $\sim$800 galaxies and integrated emission from $\sim$6000 galaxies out to 100 Mpc. These galaxies cover wide ranges of galaxy types (e.g., normal, starburst, and passive galaxies) and properties (e.g., metallicities and star-formation histories). In such galaxies, HEX-P will: (1) provide unique information about X-ray binary populations, including accretor demographics (black hole and neutron stars), distributions of accretion states and state transition cadences; (2) place order-of-magnitude more stringent constraints on inverse Compton emission associated with particle acceleration in starburst environments; and (3) put into clear context the contributions from X-ray emitting populations to both ionizing the surrounding interstellar medium in low-metallicity galaxies and heating the intergalactic medium in the $z > 8$ Universe.

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arXiv2023

Early Career Perspectives For the NASA SMD Bridge Program

In line with the Astro2020 Decadal Report State of the Profession findings and the NASA core value of Inclusion, the NASA Science Mission Directorate (SMD) Bridge Program was created to provide financial and programmatic support to efforts that work to increase the representation and inclusion of students from under-represented minorities in the STEM fields. To ensure an effective program, particularly for those who are often left out of these conversations, the NASA SMD Bridge Program Workshop was developed as a way to gather feedback from a diverse group of people about their unique needs and interests. The Early Career Perspectives Working Group was tasked with examining the current state of bridge programs, academia in general, and its effect on students and early career professionals. The working group, comprised of 10 early career and student members, analyzed the discussions and responses from workshop breakout sessions and two surveys, as well as their own experiences, to develop specific recommendations and metrics for implementing a successful and supportive bridge program. In this white paper, we will discuss the key themes that arose through our work, and highlight select recommendations for the NASA SMD Bridge Program to best support students and early career professionals.

astro-ph.IM↗

arXiv2023

The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER). V. The Structure of M33 in Resolved Stellar Populations

We present a detailed analysis of the the structure of the Local Group flocculent spiral galaxy M33, as measured using the Panchromatic Hubble Andromeda Treasury Triangulum Extended Region (PHATTER) survey. Leveraging the multiwavelength coverage of PHATTER, we find that the oldest populations are dominated by a smooth exponential disk with two distinct spiral arms and a classical central bar $-$ completely distinct from what is seen in broadband optical imaging, and the first-ever confirmation of a bar in M33. We estimate a bar extent of $\sim$1 kpc. The two spiral arms are asymmetric in orientation and strength, and likely represent the innermost impact of the recent tidal interaction responsible for M33's warp at larger scales. The flocculent multi-armed morphology for which M33 is known is only visible in the young upper main sequence population, which closely tracks the morphology of the ISM. We investigate the stability of M33's disk, finding $Q{\sim}1$ over the majority of the disk. We fit multiple components to the old stellar density distribution and find that, when considering recent stellar kinematics, M33's bulk structure favors the inclusion of an accreted halo component, modeled as a broken power-law. The best-fit halo model has an outer power-law index of $-$3 and accurately describes observational evidence of M33's stellar halo from both resolved stellar spectroscopy in the disk and its stellar populations at large radius. Integrating this profile yields a total halo stellar mass of ${\sim}5{\times}10^8\ M_{\odot}$, giving a total stellar halo mass fraction of 16%, most of which resides in the innermost 2.5 kpc.

astro-ph.GA↗

arXiv2023

Spatially-Resolved Recent Star Formation History in NGC 6946

The nearby face-on star forming spiral galaxy NGC 6946 is known as the Fireworks Galaxy due to its hosting an unusually large number of supernova. We analyze its resolved near-ultraviolet (NUV) stellar photometry measured from images taken with the Hubble Space Telescope's (HST) Wide Field Camera 3 (WFC3) with F275W and F336W filters. We model the color-magnitude diagrams (CMD) of the UV photometry to derive the spatially-resolved star formation history (SFH) of NGC 6946 over the last 25 Myr. From this analysis, we produce maps of the spatial distribution of young stellar populations and measure the total recent star formation rate (SFR) of nearly the entire young stellar disk. We find the global SFR(age$\leq$25 Myr)=$13.17 \substack{+0.91 \\-0.79} M_\odot/\rm yr$. Over this period, the SFR is initially very high ($23.39\substack{+2.43\\-2.11} M_\odot/\rm yr$ between 16-25 Myr ago), then monotonically decreases to a recent SFR of $5.31\substack{+0.19\\-0.17} M_\odot/\rm yr$ in the last 10 Myr. This decrease in global star formation rate over the last 25 Myr is consistent with measurements made with other SFR indicators. We discuss in detail two of the most active regions of the galaxy, which we find are responsible for 3% and 5% of the total star formation over the past 6.3 Myr.

astro-ph.GA↗

arXiv2023

Multiwavelength Characterization of the High Mass X-ray Binary Population of M33

We present multi-wavelength characterization of 65 high mass X-ray binary (HMXB) candidates in M33. We use the Chandra ACIS survey of M33 (ChASeM33) catalog to select hard X-ray point sources that are spatially coincident with UV-bright point source optical counterparts in the Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) catalog, which covers the inner disk of M33 at near infrared, optical, and near ultraviolet wavelengths. We perform spectral energy distribution (SED) fitting on multi-band photometry for each point source optical counterpart to measure its physical properties including mass, temperature, luminosity, and radius. We find that the majority of the HMXB companion star candidates are likely B-type main sequence stars, suggesting that the HMXB population of M33 is dominated by Be-XRBs, as is seen in other Local Group galaxies. We use spatially-resolved recent star formation history (SFH) maps of M33 to measure the age distribution of the HMXB candidate sample and the HMXB production rate for M33. We find a bimodal distribution for the HMXB production rate over the last 80 Myr, with a peak at $\sim$10 Myr and $\sim$40 Myr, which match theoretical formation timescales for the most massive HMXBs and Be X-ray binaries (Be-XRBs), respectively. We measure an HMXB production rate of 107$-$136 HMXBs/(M$_{\odot}$ yr$^{-1}$) over the last 50 Myr and 150$-$199 HMXBs/(M$_{\odot}$ yr$^{-1}$) over the last 80 Myr. For sources with compact object classifications from overlapping NuSTAR observations, we find a preference for giant/supergiant companion stars in BH-HMXBs and main sequence companion stars in neutron star HMXBs (NS-HMXBs).

astro-ph.HE↗

arXiv2023

Clusters, Clouds, and Correlations: Relating Young Clusters to Giant Molecular Clouds in M33 and M31

We use young clusters and giant molecular clouds (GMCs) in the galaxies M33 and M31 to constrain temporal and spatial scales in the star formation process. In M33, we compare the PHATTER catalogue of 1214 clusters with ages measured via colour-magnitude diagram (CMD) fitting to 444 GMCs identified from a new 35 pc resolution ALMA $^{12}$CO(2-1) survey. In M31, we compare the PHAT catalogue of 1249 clusters to 251 GMCs measured from a CARMA $^{12}$CO(1-0) survey with 20 pc resolution. Through two-point correlation analysis, we find that young clusters have a high probability of being near other young clusters, but correlation between GMCs is suppressed by the cloud identification algorithm. By comparing the positions, we find that younger clusters are closer to GMCs than older clusters. Through cross-correlation analysis of the M33 cluster data, we find that clusters are statistically associated when they are $\leq$10 Myr old. Utilizing the high precision ages of the clusters, we find that clusters older than $\approx 18$ Myr are uncorrelated with the molecular ISM. Using the spatial coincidence of the youngest clusters and GMCs in M33, we estimate that clusters spend $\approx$4-6 Myr inside their parent GMC. Through similar analysis, we find that the GMCs in M33 have a total lifetime of $\approx 11$-15 Myr. We also develop a drift model and show that the above correlations can be explained if the clusters in M33 have a 5-10 km s$^{-1}$ velocity dispersion relative to the molecular ISM.

astro-ph.GA↗

arXiv2023

The Spatial Correlation of High Mass X-ray Binaries and Young Star Clusters in Nearby Star-Forming Galaxies

We present an analysis of the two-point spatial correlation functions of high-mass X-ray binary (HMXB) and young star cluster (YSC) populations in M31 and M33. We find evidence that HMXBs are spatially correlated with YSCs to a higher degree than would be expected from random chance in both galaxies. When supplemented with similar studies in the Milky Way, Small Magellanic Cloud, and NGC 4449, we find that the peak value of the spatial correlation function correlates strongly with the specific star formation rate of the host galaxy. We additionally perform an X-ray stacking analysis of 211 non-X-ray detected YSCs in M31 and 463 YSCs in M33. We do not detect excess X-ray emission at the stacked cluster locations down to 3$σ$ upper limits of $\sim10^{33}$ erg s$^{-1}$ (0.35-8 keV) in both galaxies, which strongly suggests that dynamical formation within YSCs is not a major HMXB formation channel. We interpret our results in the context of (1) the recent star formation histories of the galaxies, which may produce differences in the demographics of compact objects powering the HMXBs, and (2) the differences in natal kicks experienced by compact objects during formation, which can eject newly-formed HMXB from their birth clusters.

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arXiv2023

A new sample of transient ultraluminous X-ray sources serendipitously discovered by Swift/XRT

Ultraluminous X-ray sources (ULXs) are our best laboratories for studying extreme super-Eddington accretion. Most studies of these objects are of relatively persistent sources, however there is growing evidence to suggest a large fraction of these sources are transient. Here we present a sample of five newly reported transient ULXs in the galaxies NGC 4945, NGC 7793 and M81 serendipitously discovered in Swift/XRT observations. Swift monitoring of these sources have provided well sampled lightcurves, allowing for us to model the lightcurves with the disk instability model of Hameury & Lasota (2020) which implies durations of 60-400 days and that the mass accretion rate through the disk is close to or greater than the Eddington rate. Of the three source regions with prior HST imaging, color magnitude diagrams of the potential stellar counterparts show varying ages of the possible stellar counterparts. Our estimation of the rates of these sources in these three galaxies is 0.4-1.3 year$^{-1}$. We find that while persistent ULXs dominate the high end of galaxy luminosity functions, the number of systems that produce ULX luminosities are likely dominated by transient sources.

astro-ph.HE↗

arXiv2023

The Masses of Supernova Remnant Progenitors in M33

Using resolved optical stellar photometry from the Panchromatic Hubble Andromeda Treasury Triangulum Extended Region (PHATTER) survey, we measured the star formation history (SFH) near the position of 85 supernova remnants (SNRs) in M33. We constrained the progenitor masses for 60 of these SNRs, finding the remaining 25 remnants had no local SF in the last 56 Myr consistent with core-collapse SNe (CCSNe), making them potential Type Ia candidates. We then infer a progenitor mass distribution from the age distribution, assuming single star evolution. We find that the progenitor mass distribution is consistent with being drawn from a power-law with an index of $-2.9^{+1.2}_{-1.0}$. Additionally, we infer a minimum progenitor mass of $7.1^{+0.1}_{-0.2}\ M_{\odot}$ from this sample, consistent with several previous studies, providing further evidence that stars with ages older than the lifetimes of single 8 $M_{\odot}$ stars are producing supernovae.

astro-ph.HE↗

arXiv2023

X-ray luminosity function of high-mass X-ray binaries: Studying the signatures of different physical processes using detailed binary evolution calculations

The ever-expanding observational sample of X-ray binaries (XRBs) makes them excellent laboratories for constraining binary evolution theory. Such constraints can be obtained by studying the effects of various physical assumptions on synthetic X-ray luminosity functions (XLFs) and comparing to observed XLFs. In this work, we focus on high-mass XRBs (HMXBs) and study the effects on the XLF of various, poorly-constrained assumptions regarding physical processes such as the common-envelope phase, the core-collapse, and wind-fed accretion. We use the new binary population synthesis code POSYDON, which employs extensive pre-computed grids of detailed stellar structure and binary evolution models, to simulate the evolution of binaries. We generate 96 synthetic XRB populations corresponding to different combinations of model assumptions. The generated HMXB XLFs are feature-rich, deviating from the commonly assumed single-power law. We find a break in our synthetic XLF at luminosity $\sim 10^{38}$ erg s$^{-1}$, similar to observed XLFs. However, we find also a general overabundance of XRBs (up to a factor of $\sim$10 for certain model parameter combinations) driven primarily by XRBs with black hole accretors. Assumptions about the transient behavior of Be-XRBs, asymmetric supernova kicks, and common-envelope physics can significantly affect the shape and normalization of our synthetic XLFs. We find that less well-studied assumptions regarding the circularization of the orbit at the onset of Roche-lobe overflow and criteria for the formation of an X-ray emitting accretion disk around wind-accreting black holes can also impact our synthetic XLFs. Our study reveals the importance of large-scale parameter studies, highlighting the power of XRBs in constraining binary evolution theory.

astro-ph.HE↗

arXiv2023

Science with the Ultraviolet Explorer (UVEX)

UVEX is a proposed medium class Explorer mission designed to provide crucial missing capabilities that will address objectives central to a broad range of modern astrophysics. The UVEX design has two co-aligned wide-field imagers operating in the FUV and NUV and a powerful broadband medium resolution spectrometer. In its two-year baseline mission, UVEX will perform a multi-cadence synoptic all-sky survey 50/100 times deeper than GALEX in the NUV/FUV, cadenced surveys of the Large and Small Magellanic Clouds, rapid target of opportunity followup, as well as spectroscopic followup of samples of stars and galaxies. The science program is built around three pillars. First, UVEX will explore the low-mass, low-metallicity galaxy frontier through imaging and spectroscopic surveys that will probe key aspects of the evolution of galaxies by understanding how star formation and stellar evolution at low metallicities affect the growth and evolution of low-metallicity, low-mass galaxies in the local universe. Such galaxies contain half the mass in the local universe, and are analogs for the first galaxies, but observed at distances that make them accessible to detailed study. Second, UVEX will explore the dynamic universe through time-domain surveys and prompt spectroscopic followup capability will probe the environments, energetics, and emission processes in the early aftermaths of gravitational wave-discovered compact object mergers, discover hot, fast UV transients, and diagnose the early stages of stellar explosions. Finally, UVEX will become a key community resource by leaving a large all-sky legacy data set, enabling a wide range of scientific studies and filling a gap in the new generation of wide-field, sensitive optical and infrared surveys provided by the Rubin, Euclid, and Roman observatories. This paper discusses the scientific potential of UVEX, and the broad scientific program.

astro-ph.GA↗

arXiv2022

The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) II. The Spatially Resolved Recent Star Formation History of M33

We measure the spatially resolved recent star formation history (SFH) of M33 using optical images taken with the Hubble Space Telescope as part of the Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) survey. The area covered by the observations used in this analysis covers a de-projected area of $\sim$38 kpc$^{2}$ and extends to $\sim$3.5 and $\sim$2 kpc from the center of M33 along the major and semi-major axes, respectively. We divide the PHATTER optical survey into 2005 regions that measure 24 arcsec, $\sim$100 pc, on a side and fit color magnitude diagrams for each region individually to measure the spatially resolved SFH of M33 within the PHATTER footprint. There are significant fluctuations in the SFH on small spatial scales and also galaxy-wide scales that we measure back to about 630 Myr ago. We observe a more flocculent spiral structure in stellar populations younger than about 80 Myr, while the structure of the older stellar populations is dominated by two spiral arms. We also observe a bar in the center of M33, which dominates at ages older than about 80 Myr. Finally, we find that the mean star formation rate (SFR) over the last 100 Myr within the PHATTER footprint is 0.32$\pm$0.02 M$_{\odot}$ yr$^{-1}$. We measure a current SFR (over the last 10 Myr) of 0.20$\pm$0.03 M$_{\odot}$ yr$^{-1}$. This SFR is slightly higher than previous measurements from broadband estimates, when scaled to account for the fraction of the D25 area covered by the PHATTER survey footprint.

astro-ph.GA↗