ABSTRACT
We present a method to self-consistently propagate stellar-mass $\hbox{$\hbox{${\rm M}$}_{\star }$}=\log (\hbox{${\rm M}$}/\hbox{${\rm M}_{\odot }$})$ and star-formation-rate $\hbox{${\Psi ...}$}=\log (\hbox{${\psi }$}/\hbox{${\rm M}_{\odot }$}\, {\rm yr}^{-1}$) uncertainties on to intercept (α), slope (β), and intrinsic-scatter (σ) estimates for a simple model of the main sequence of star-forming galaxies, where $\hbox{${\Psi }$}= \alpha + \beta \hbox{$\hbox{${\rm M}$}_{\star }$}+ \mathcal {N}(0,\sigma)$. To test this method and compare it with other published methods, we construct mock photometric samples of galaxies at z ∼ 5 based on idealized models combined with broad- and medium-band filters at wavelengths 0.8–5 μm. Adopting simple Ψ estimates based on dust-corrected ultraviolet luminosity can underestimate σ. We find that broad-band fluxes alone cannot constrain the contribution from emission lines, implying that strong priors on the emission-line contribution are required if no medium-band constraints are available. Therefore, at high redshifts, where emission lines contribute a higher fraction of the broad-band flux, photometric fitting is sensitive to Ψ variations on short (∼10 Myr) time-scales. Priors on age imposed with a constant (or rising) star formation history (SFH) do not allow one to investigate a possible dependence of σ on $\hbox{${\rm M}$}_{\star }$ at high redshifts. Delayed exponential SFHs have less constrained priors, but do not account for Ψ variations on short time-scales, a problem if σ increases due to stochasticity of star formation. A simple SFH with current star formation decoupled from the previous history is appropriate. We show that, for simple exposure-time calculations assuming point sources, with low levels of dust, we should be able to obtain unbiased estimates of the main sequence down to $\mathrm{ log}(\hbox{${\rm M}$}/\hbox{${\rm M}_{\odot }$})\sim 8$ at z ∼ 5 with the James Webb Space Telescope while allowing for stochasticity of star formation.
ABSTRACT
The Hubble Frontier Fields represent the opportunity to probe the high-redshift evolution of the main sequence of star-forming galaxies to lower masses than possible in blank fields thanks ...to foreground lensing of massive galaxy clusters. We use the beagle SED-fitting code to derive stellar masses, $\rm{{M_{\star }}}=\log ({\it M}/{\rm{M_{\odot }}})$, SFRs, $\rm{{\Psi }}=\log (\rm{{\psi }}/{\rm{M_{\odot }}}\, {\rm{yr}}^{-1})$, and redshifts from galaxies within the astrodeep catalogue. We fit a fully Bayesian hierarchical model of the main sequence over 1.25 < z < 6 of the form $\rm{{\Psi }}= \rm{\alpha _\mathrm{9.7}}(z) + \rm{\beta }({\rm{M_{\star }}}-9.7) + \mathcal {N}(0,\rm{\sigma }^2)$ while explicitly modelling the outlier distribution. The redshift-dependent intercept at $\rm{{M_{\star }}}=9.7$ is parametrized as $\rm{\alpha _\mathrm{9.7}}(z) = \log {\it N}(1+{\it z})^{\rm{\gamma }} + 0.7$. Our results agree with an increase in normalization of the main sequence to high redshifts that follows the redshift-dependent rate of accretion of gas on to dark matter haloes with $\rm{\gamma }=2.40^{+0.18}_{-0.18}$. We measure a slope and intrinsic scatter of $\rm{\beta }=0.79^{+0.03}_{-0.04}$ and $\rm{\sigma }=0.26^{+0.02}_{-0.02}$. We find that the sampling of the SED provided by the combination of filters (Hubble + ground-based Ks-band + Spitzer 3.6 and 4.5 μm) is insufficient to constrain M⋆ and Ψ over the full dynamic range of the observed main sequence, even at the lowest redshifts studied. While this filter set represents the best current sampling of high-redshift galaxy SEDs out to z > 3, measurements of the main sequence to low masses and high redshifts still strongly depend on priors employed in SED fitting (as well as other fitting assumptions). Future data sets with JWST should improve this.
ABSTRACT
We study the ionizing photon production efficiency at the end of the Epoch of Reionization (z ∼ 5.4 − 6.6) for a sample of 30 Ly α emitters. This is a crucial quantity to infer the ionizing ...photon budget of the universe. These objects were selected to have reliable spectroscopic redshifts, assigned based on the profile of their Ly α emission line, detected in the MUSE deep fields. We exploit medium-band observations from the JWST Extragalactic Medium-band Survey (JEMS) to find the flux excess corresponding to the redshifted Hα emission line. We estimate the ultraviolet (UV) luminosity by fitting the full JEMS photometry, along with several HST photometric points, with Prospector. We find a median UV continuum slope of $\beta = -2.09^{+0.23}_{-0.21}$, indicating young stellar populations with little-to-no dust attenuation. Supported by this, we derive ξion,0 with no dust attenuation and find a median value of log$\frac{\xi _{ion,0}}{\text{Hz erg}^{-1}} = 25.44^{+0.21}_{-0.15}$. If we perform dust attenuation corrections and assume a Calzetti attenuation law, our values are lowered by ∼0.1 dex. Our results suggest Ly α emitters at the Epoch of Reionization have slightly enhanced ξion,0 compared to previous estimations from literature, in particular, when compared to the non-Ly α emitting population. This initial study provides a promising outlook on the characterization of ionizing photon production in the early universe. In the future, a more extensive study will be performed on the entire data set provided by the JWST Advanced Deep Extragalactic Survey (JADES). Thus, for the first time, allowing us to place constraints on the wider galaxy populations driving reionization.
Well-known in educational circles is the terminology that encapsulates the achievement discrepancy between white and Black students. The so-called achievement gap, the signature language used to ...represent the different achievement levels, challenges educators everywhere to find best practices to attend to the needs and interests of Black students. With dubious beginnings, the achievement gap arguably began during the period of American history when black people were enslaved and disallowed to educate themselves with even the most basic literacy components. This writing traces the lineage of black literacy from the mid-1700s to the present and makes the case that there is no achievement gap, there only exists a so-called achievement gap that has continually proven harmful to Black children. Accordingly, this article uses BlackCrit to examine the so-called achievement gap and to offer suggestions for mitigating its impact in educational environments.
While some lament and disparage the use of Black English (BE), particularly in educational spaces, the purpose, power, and pragmatism of BE are elucidated in this manuscript in an effort to bring all ...educators into the knowledge of its potency and richness. Using Gee’s work on primary and secondary discourse as a foundation, this manuscript offers a chronology of BE, discusses its impact and usage as a mother tongue, and describes its importance in contemporary education, leveraging hip hop, rap music, in particular, as an instructional tool to substantiate the legitimacy of the BE as an already legitimate, viable dialect natively spoken by generations of Black people. This manuscript also invites readers to consider the value of BE in developing strong twenty-one-century learners by establishing multiliterate students who are conversant in an array of spoken languages/dialects and cultural nuances.
The accuracy of magnetic resonance (MR) imaging in staging invasive carcinoma of the cervix was determined retrospectively in 57 consecutive patients in whom the extent of disease was surgically ...confirmed. MR images were analyzed for (a) location and size of the primary tumor; (b) tumor extension to the uterine corpus, vagina, parametria, pelvic sidewall, bladder, or rectum; and (c) pelvic lymphadenopathy. The accuracy of MR imaging in determination of tumor location was 91% and for determination of tumor size within 0.5 cm, 70%. Its accuracy was 93% for vaginal extension and 88% for parametrial extension. Pelvic sidewall, bladder, and rectal involvement were accurately excluded in all patients, but the positive predictive values were 75%, 67%, and 100%, respectively. Overall, the accuracy of MR imaging in staging was 81%. MR imaging is valuable because it can accurately demonstrate tumor location, tumor size, degree of stromal penetration, and lower uterine segment involvement. It is also valuable for ruling out parametrial, pelvic sidewall, bladder, and rectal involvement.
The purpose of this prospective clinical trial was to determine the reliability of the Pipelle endometrial biopsy instrument in recovering adequate tissue for confirmation of the diagnosis of ...endometrial cancer in patients with known endometrial carcinoma, and to compare endometrial histology of the sampling specimen with that of the subsequent hysterectomy specimen. Forty patients were enrolled in this study. All biopsies were performed in the office without anesthesia. The patients had a median age of 62 years (range 40-83). Discomfort was reported by the patient as mild, moderate, or severe; only two patients (5.0%) reported severe pain. There were no complications experienced with endometrial sampling. Thirty-nine of 40 specimens (97.5%) confirmed endometrial carcinoma; therefore, this study yielded a 97.5% sensitivity for the Pipelle endometrial sampling device. Comparing Pipelle and hysterectomy histology for individual patients, the histologic grade was the same in 29 (74.4%), while the Pipelle demonstrated a more advanced degree of differentiation in five (12.8%) and a lesser degree in five (12.8%). There was no residual tumor identified in one hysterectomy specimen (2.5%). Among the 12 patients who had a D&C for diagnostic purposes before referral, the Pipelle biopsy correlated with the D&C histology in ten of 12 (83.3%) and revealed a more advanced grade of tumor in one (8.3%) and a more differentiated grade in one (8.3%). In one patient, the D&C histology was adenocarcinoma grade 1, with the Pipelle demonstrating atypical hyperplasia and the hysterectomy specimen interpreted as endometrial adenocarcinoma in situ. This study demonstrates the Pipelle to be an accurate device for endometrial sampling in patients with endometrial carcinoma.
Genetic factors are clearly integral to the etiology of neoplasia. A cancer family syndrome (Lynch syndrome II) consisting of uterine, colon, and ovarian cancer is recognized, but the heritability of ...isolated endometrial adenocarcinoma has not otherwise been thoroughly investigated. We have performed pedigree studies in index cases with endometrial adenocarcinoma, using spouses as controls. Preliminary results from 64 probands showed four families in which endometrial adenocarcinoma was diagnosed in at least one first-degree relative of the proband (mother, daughter, sister); none showed relatives with colon or ovarian cancer. In none of the 34 control pedigrees did either a mother or sister have endometrial adenocarcinoma. In four other families, multiple first- and second-degree relatives of probands had adenocarcinoma of the uterus, colon, or ovary, presumably representing a cancer family syndrome (Lynch syndrome II).
Our preliminary data not only show familial and probably heritable tendencies for endometrial adenocarcinoma, but further suggest that there are at least two distinct forms: (1) the previously described Lynch syndrome II (cancer family syndrome), and (2) a heretofore unemphasized entity characterized by a tendency to endometrial adenocarcinoma alone.
We present a method to self-consistently propagate M\(_{*}\) and SFR (\(\Psi\)) uncertainties onto intercept, slope and intrinsic scatter estimates for a simple model of the main sequence of star ...forming galaxies where \(\Psi = \alpha + \beta\)M\(_{*} + \mathcal{N}(0,\sigma)\). From simple idealised models set up with broad-band photometry from NIRCam filters at \(z\sim5\), we test the method and compare to methods in the literature. Simplifying the \(\Psi\) estimate by basing it on dust-corrected MUV can help to reduce the impact of template set degeneracies on slope and intercept estimates, but act to bias the intrinsic scatter estimate. We find that broad-band fluxes alone cannot constrain the contribution from emission lines, implying that strong priors on the emission-line contribution are required if no medium-band constraints are available. Therefore at high redshifts, where emission lines contribute a higher fraction of the broad-band flux, photometric fitting is sensitive to \(\Psi\) variations on short (\(\sim\) 10 Myr) timescales. Priors on age imposed with a constant (or rising) star formation history (SFH) do not allow one to investigate a possible dependence of \(\sigma\) on M\(_{*}\) at high redshifts. Delayed exponential SFHs have less constrained priors, but do not account for \(\Psi\) variations on short timescales, a problem if \(\sigma\) increases due to stochasticity of star formation. A simple SFH with current star formation decoupled from the previous history is appropriate. We show that, for simple exposure-time calculations assuming point sources, with low levels of dust, we should be able to obtain unbiased estimates of the main sequence down to log(M/M\(_{\odot}\)) \(\sim\) 8 at \(z\sim5\) with the James Webb Space Telescope while allowing for stochasticity of star formation.
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