分类： 天文学 >> 天文学 提交时间： 2023-02-19
Jed McKinney
Luke Finnerty
Caitlin Casey
Maximilien Franco
Arianna Long
Seiji Fujimoto
Jorge Zavala
Olivia Cooper
Hollis Akins
Alexandra Pope
Lee Armus
B. T. Soifer
Kirsten Larson
Keith Matthews
Jason Melbourne
Michael Cushing
摘要： Selecting the first galaxies at z>7-10 from JWST surveys is complicated by z7-10 Lyman Break Galaxies (LBGs). Dust-obscured 3-1.5$ and z>4. While there are some redshifts (z~3.75) where our stack is more degenerate with the photometry of z>10 LBGs between $\lambda_{rest}\sim0.3-0.8\,\mu$m, redder filter coverage beyond $\lambda_{obs}>3.5\,\mu$m and far-IR/sub-mm follow-up may be useful for breaking the degeneracy and making a crucial separation between two fairly unconstrained populations, dust-obscured galaxies at z~3-6 and LBGs at z>10.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Hanae Inami
Jason Surace
Lee Armus
Aaron S. Evans
Kirsten L. Larson
Loreto Barcos-Munoz
Sabrina Stierwalt
Joseph M. Mazzarella
George C. Privon
Yiqing Song
Sean Linden
Christopher C. Hayward
Torsten Boker
Vivian U
Thomas Bohn
Vassilis Charmandaris
Tanio Diaz-Santos
Justin H. Howell
Thomas Lai
Anne M. Medling
摘要： We have used the Mid-InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST) to obtain the first spatially resolved, mid-infrared (mid-IR) images of IIZw096, a merging luminous infrared galaxy (LIRG) at $z = 0.036$. Previous observations with the Spitzer Space Telescope suggested that the vast majority of the total IR luminosity (LIR) of the system originated from a small region outside of the two merging nuclei. New observations with JWST/MIRI now allow an accurate measurement of the location and luminosity density of the source that is responsible for the bulk of the IR emission. We estimate that 40-70% of the IR bolometric luminosity, or $3-5 \times 10^{11}\,{\rm{L_{\odot}}}$, arises from a source no larger than 175pc in radius, suggesting a luminosity density of at least $3-5 \times 10^{12} \, {\rm{L_{\odot} \, kpc^{-2}}}$. In addition, we detect 11 other star forming sources, five of which were previously unknown. The MIRI F1500W/F560W colors of most of these sources, including the source responsible for the bulk of the far-IR emission, are much redder than the nuclei of local LIRGs. These observations reveal the power of JWST to disentangle the complex regions at the hearts of merging, dusty galaxies.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Yun Wang
Lee Armus
Andrew Benson
Emanuele Daddi
Andreas Faisst
Anthony Gonzalez
Casey Papovich
Zoran Ninkov
Massimo Robberto
Randall J. Rose
Thomas
Rose
Claudia Scarlata
S. A. Stanford
Todd Veach
Zhongxu Zhai
Bradford Benson
L. E. Bleem
Michael W. Davis
George Helou
摘要： ISCEA (Infrared Satellite for Cosmic Evolution Astrophysics) is a small astrophysics mission whose Science Goal is to discover how galaxies evolved in the cosmic web of dark matter at cosmic noon. Its Science Objective is to determine the history of star formation and its quenching in galaxies as a function of local density and stellar mass when the Universe was 3-5 Gyrs old (1.2 10 Mpc in each of 50 protocluster (cluster and cosmic web) fields at 1.2 < z < 2.1. ISCEA measures the star formation quenching factor in those fields, and galaxy kinematics with a precision < 50 km/s to deduce the 3D spatial distribution in each field. ISCEA will transform our understanding of galaxy evolution at cosmic noon. ISCEA is a small satellite observatory with a 30cm equivalent diameter aperture telescope with a FoV of 0.32 deg^2, and a multi-object spectrograph with a digital micro-mirror device (DMD) as its programmable slit mask. ISCEA will obtain spectra of 1000 galaxies simultaneously at an effective resolving power of R=1000, with 2.8"x2.8" slits, over the NIR wavelength range of 1.1 to 2.0 microns, a regime not accessible from the ground without large gaps in coverage. ISCEA will achieve a pointing accuracy of <= 2" FWHM over 200s. ISCEA will be launched into a Low Earth Orbit, with a prime mission of 2.5 years. ISCEA's space-qualification of DMDs opens a new window for spectroscopy from space, enabling revolutionary advances in astrophysics.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Sean T. Linden
Aaron S. Evans
Lee Armus
Jeffrey A. Rich
Kirsten L. Larson
Thomas Lai
George C. Privon
Vivian U
Hanae Inami
Thomas Bohn
Yiqing Song
Loreto Barcos-Muñoz
Vassilis Charmandaris
Anne M. Medling
Sabrina Stierwalt
Tanio Diaz-Santos
Torsten Böker
Paul van der Werf
Susanne Aalto
Philip Appleton
摘要： We present the results of a {\it James Webb Space Telescope} NIRCam investigation into the young massive star cluster (YMC) population in the luminous infrared galaxy VV 114. We identify 374 compact YMC candidates with a $S/N \geq 3$, 5, and 5 at F150W, F200W, and F356W respectively. A direct comparison with our {\it HST} cluster catalog reveals that $\sim 20\%$ of these sources are undetected at optical wavelengths. Based on {\it yggdrasil} stellar population models, we identify 17 YMC candidates in our {\it JWST} imaging alone with F150W-F200W and F200W-F356W colors suggesting they are all very young, dusty ($A_{V} = 5 - 15$), and massive ($10^{5.8} < M_{\odot} < 10^{6.1}$). The discovery of these `hidden' sources, many of which are found in the `overlap' region between the two nuclei, quadruples the number of $t < 3$ Myr clusters, and nearly doubles the number of $t < 6$ Myr clusters detected in VV 114. Now extending the cluster age distribution ($dN/d\tau \propto \tau^{\gamma}$) to the youngest ages, we find a slope of $\gamma = -1.30 \pm 0.39$ for $10^{6} < \tau (\mathrm{yr}) < 10^{7}$, which is consistent with the previously determined value from $10^{7} < \tau (\mathrm{yr}) < 10^{8.5}$, and confirms that VV 114 has a steep age distribution slope for all massive star clusters across the entire range of cluster ages observed. Finally, the consistency between our {\it JWST}- and {\it HST}-derived age distribution slopes indicates that the balance between cluster formation and destruction has not been significantly altered in VV 114 over the last 0.5 Gyr.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Vivian U
Thomas Lai
Marina Bianchin
Raymond P. Remigio
Lee Armus
Kirsten L. Larson
Tanio Diaz-Santos
Aaron Evans
Sabrina Stierwalt
David R. Law
Matthew A. Malkan
Sean Linden
Yiqing Song
Paul P. van der Werf
Tianmu Gao
George C. Privon
Anne M. Medling
Loreto Barcos-Muñoz
Christopher C. Hayward
Hanae Inami
摘要： The nearby, luminous infrared galaxy (LIRG) NGC 7469 hosts a Seyfert nucleus with a circumnuclear star-forming ring and is thus the ideal local laboratory for investigating the starburst--AGN connection in detail. We present integral-field observations of the central 1.3 kpc region in NGC 7469 obtained with the JWST Mid-InfraRed Instrument. Molecular and ionized gas distributions and kinematics at a resolution of {\sim}100 pc over the 4.9 - 7.6{\mu}m region are examined to study gas dynamics influenced by the central AGN. The low-ionization [Fe II] {\lambda}5.34{\mu}m and [Ar II] {\lambda}6.99{\mu}m lines are bright on the nucleus and in the starburst ring, as opposed to H2 S(5) {\lambda}6.91{\mu}m which is strongly peaked at the center and surrounding ISM. The high-ionization [Mg V] line is resolved and shows a broad, blueshifted component associated with the outflow. It has a nearly face-on geometry that is strongly peaked on the nucleus, where it reaches a maximum velocity of -650 km/s, and extends about 400 pc to the East. Regions of enhanced velocity dispersion in H2 and [Fe II] {\sim}180 pc from the AGN that also show high L(H2)/L(PAH) and L([Fe II])/L(Pf{\alpha}) ratios to the W and N of the nucleus pinpoint regions where the ionized outflow is depositing energy, via shocks, into the dense interstellar medium between the nucleus and the starburst ring. These resolved mid-infrared observations of the nuclear gas dynamics demonstrate the power of JWST and its high-sensitivity integral-field spectroscopic capability to resolve feedback processes around supermassive black holes in the dusty cores of nearby LIRGs.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Thomas Bohn
Hanae Inami
Tanio Diaz-Santos
Lee Armus
Sean T. Linden
Vivian U
Jason Surace
Kirsten L. Larson
Aaron S. Evans
Shunshi Hoshioka
Thomas Lai
Yiqing Song
Joseph M. Mazzarella
Loreto Barcos-Munoz
Vassilis Charmandaris
Justin H. Howell
Anne M. Medling
George C. Privon
Jeffrey A. Rich
Sabrina Stierwalt
摘要： We present James Webb Space Telescope (JWST) imaging of NGC 7469 with the Near-Infrared Camera (NIRCam) and the Mid-InfraRed Instrument (MIRI). NGC 7469 is a nearby, $z=0.01627$, luminous infrared galaxy (LIRG) that hosts both a Seyfert Type-1.5 nucleus and a circumnuclear starburst ring with a radius of $\sim$0.5 kpc. The new near-infrared (NIR) JWST imaging reveals 66 star-forming regions, 37 of which were not detected by HST observations. Twenty-eight of the 37 sources have very red NIR colors that indicate obscurations up to A$_{\rm{v}}\sim7$ and a contribution of at least 25$\%$ from hot dust emission to the 4.4$\mu$m band. Their NIR colors are also consistent with young ($<$5 Myr) stellar populations and more than half of them are coincident with the MIR emission peaks. These younger, dusty star-forming regions account for $\sim$6$\%$ and $\sim$17$\%$ of the total 1.5$\mu$m and 4.4$\mu$m luminosity of the starburst ring, respectively. Thanks to JWST, we find a significant number of young dusty sources that were previously unseen due to dust extinction. The newly identified 28 young sources are a significant increase compared to the number of HST-detected young sources (4-5). This makes the total percentage of the young population rise from $\sim$15$\%$ to 48$\%$. These results illustrate the effectiveness of JWST in identifying and characterizing previously hidden star formation in the densest star-forming environments around AGN.
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