Nicha Leethochawalit
A5028893953- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Radio Astronomy Observations and Technology
- Remote Sensing in Agriculture
- Advanced Thermodynamic Systems and Engines
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Phase Equilibria and Thermodynamics
- Geomagnetism and Paleomagnetism Studies
- Methane Hydrates and Related Phenomena
- Cosmology and Gravitation Theories
- Advanced Vision and Imaging
National Astronomical Research Institute of Thailand
2019-2024
ARC Centre of Excellence for All-sky Astrophysics
2019-2024
ASTRO-3D
2019-2024
The University of Melbourne
2019-2024
California Institute of Technology
2015-2019
University of Chicago
2012
We present the results of a first search for galaxy candidates at z$\sim$9--15 on deep seven-bands NIRCam imaging acquired as part GLASS-JWST Early Release Science Program flanking field Frontier Fields cluster A2744. Candidates are selected via two different renditions Lyman-break technique, isolating objects z$\sim$9-11, and z$\sim$9-15, respectively, supplemented by photometric redshifts obtained with independent codes. find five color-selected z$>$9, plus one additional candidate...
The GLASS James Webb Space Telescope Early Release Science (hereafter GLASS-JWST-ERS) Program will obtain and make publicly available the deepest extragalactic data of ERS campaign. It is primarily designed to address two key science questions, namely, "what sources ionized universe when?" "how do baryons cycle through galaxies?", while also enabling a broad variety first look scientific investigations. In primary mode, it NIRISS NIRSpec spectroscopy galaxies lensed by foreground Hubble...
We report the detection of a high density redshift $z\approx 10$ galaxies behind foreground cluster Abell 2744, selected from imaging data obtained recently with NIRCam onboard {\it JWST} by three programs -- GLASS-JWST, UNCOVER, and DDT\#2756. To ensure robust estimates lensing magnification $\mu$, we use an improved version our model that exploits first epoch images newly MUSE spectra, avoids regions $\mu>5$ where uncertainty may be higher. detect seven bright demagnified rest-frame $-22...
Abstract We present the spectroscopic confirmation of a protocluster at z = 7.88 behind galaxy cluster Abell 2744 (hereafter A2744-z7p9OD). Using JWST NIRSpec, we find seven galaxies within projected radius 60 kpc. Although reside in an overdensity around ≳20× greater than random volume, they do not show strong Ly α emission. place 2 σ upper limits on rest-frame equivalent width <16–28 Å. Based tight to emission, constrain volume-averaged neutral fraction hydrogen intergalactic medium be...
Abstract We exploit James Webb Space Telescope (JWST) NIRCam observations from the GLASS-JWST-Early Release Science program to investigate galaxy stellar masses at z > 7. first show that JWST reduce uncertainties on mass by a factor of least 5–10, when compared with highest-quality data sets available date. then study UV mass-to-light ratio, finding galaxies exhibit two orders magnitude range M / L values for given luminosity, indicative broad variety physical conditions and star...
We present the first James Webb Space Telescope/NIRCam-led determination of $7<z<9$ galaxy properties based on broadband imaging from 0.8 to 5~$\mathrm{\mu m}$ as part GLASS-JWST Early Release Science program. This is deepest dataset acquired at these wavelengths date, with an angular resolution $\lesssim0.14$ arcsec. robustly identify 13 galaxies $S/N\gtrsim8$ in F444W 8 arcmin$^2$ data $m_{AB}\leq 28$ a combination dropout and photometric redshift selection. From simulated modeling, we...
Abstract We present a comprehensive search and analysis of high-redshift galaxies in suite nine public JWST extragalactic fields taken Cycle 1, covering total effective area <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>∼</mml:mo> <mml:mn>358</mml:mn> <mml:mspace width="0.25em"/> <mml:msup> <mml:mrow> <mml:mi>arcmin</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msup> </mml:math> . Through conservative (8 σ ) photometric selection, we identify 341 at 5...
ABSTRACT We discuss spatially resolved emission line spectroscopy secured for a total sample of 15 gravitationally lensed star-forming galaxies at mean redshift <?CDATA $z\simeq 2$?> <?MML <mml:math> <mml:mi>z</mml:mi> <mml:mo>≃</mml:mo> <mml:mn>2</mml:mn> </mml:math>?> based on Keck laser-assisted adaptive optics observations undertaken with the recently improved OSIRIS integral field unit (IFU) spectrograph. By exploiting sources drawn primarily from CASSOWARY survey, we these sub-L...
We present the first rest-frame optical size-luminosity relation of galaxies at $z>7$, using NIRCam imaging data obtained by GLASS James Webb Space Telescope Early Release Science (GLASS-JWST-ERS) program, providing deepest extragalactic ERS campaign. Our sample consist 19 photometrically selected bright with $m_\text{F444W}\leq27.8$ $7<z<9$ and $m_\text{F444W}<28.2$ $z\sim9-15$. measure size in 5 bands, from ($\sim4800\,{\rm \AA}$) to ultra-violet (UV; $\sim1600\,{\rm based on S\'ersic...
ABSTRACT The JWST has discovered a surprising abundance of bright galaxy candidates in the very early universe (≤500 Myr after Big Bang), calling into question current formation models. Spectroscopy is needed to confirm primeval nature these candidates, as well understand how first galaxies form stars and grow. Here we present deep spectroscopic continuum ALMA observations towards GHZ2/GLASS-z12, one brightest most robust at z &gt; 10, identified GLASS-JWST Early Release Science Program....
We present the reduced images and multi-wavelength catalog of first JWST NIRCam extra-galactic observations from GLASS Early Release Science Program, obtained as coordinated parallels NIRISS Abell 2744 cluster. Images in seven bands (F090W, F115W, F150W, F200W, F277W, F356W, F444W) have been using an augmented version official pipeline; we discuss procedures adopted to remove or mitigate defects raw images. obtain a multi--band by means forced aperture photometry on PSF-matched at position...
Star-forming galaxies can exhibit strong morphological differences between the rest-frame far-UV and optical, reflecting inhomogeneities in star-formation dust attenuation. We exploit deep, high resolution NIRCAM 7-band observations to take a first look at morphology of epoch reionization ($z>7$), its variation wavelength range Lyman $\alpha$ 6000-4000\AA, $z=7-12$. find no dramatic variations with -- kind that would have overturned anything we learned from Hubble Space Telescope. No...
We use the GLASS-JWST Early Release Science NIRCam parallel observations to provide a first view of UV continuum properties NIRCam/F444W selected galaxies at 4<z<7. By combining multiwavelength observations, we constrain slope for sample 401 with stringent quality controls. find that >99% are blue star-forming very low levels dust (Avbeta~0.01+/-0.33). no statistically significant correlation redshift or magnitude. However, in general higher redshifts and fainter magnitudes have steeper...
We present images and a multi-wavelength photometric catalog based on all of the JWST NIRCam observations obtained to date in region Abell 2744 galaxy cluster. These data come from three different programs, namely GLASS-JWST Early Release Science Program, UNCOVER, Director's Discretionary Time program 2756. The observed area wide-band filters - covering central extended regions cluster, as well new parallel fields is 46.5 arcmin$^2$ total. All eight bands (F090W, F115W, F150W, F200W, F277W,...
Abstract We present deep JWST NIRSpec observations in the sight line of MACS J1149.5+2223, a massive cluster galaxies at z = 0.54. report spectroscopic redshift 28 sources 3 < 9.1, including nine with detection <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mfenced close="]" open="["> <mml:mi mathvariant="normal">O</mml:mi> <mml:mspace width="0.25em"/> mathsize="small" mathvariant="normal">III</mml:mi> </mml:mrow> </mml:mfenced>...
We report the first gas-phase metallicity map of a distant galaxy measured with James Webb Space Telescope (JWST). use NIRISS slitless spectroscopy acquired by GLASS Early Release Science program to spatially resolve rest-frame optical nebular emission lines in gravitationally lensed at $z=3.06$ behind Abell 2744 cluster. This (dubbed GLASS-Zgrad1) has stellar mass $\sim10^{8.6} M_\odot$, instantaneous star formation rate $\sim8.6$ $M_\odot$/yr (both corrected for lensing magnification), and...
Abstract We present the largest systematic, Hubble Space Telescope (HST)–based search to date for luminous z ≳ 8 galaxy candidates using ∼1267 arcmin 2 of (pure-)parallel observations from a compilation 288 random sightlines with Advanced Camera Surveys and Wide Field 3 observations, derived (Super)Brightest Reionizing Galaxies (SuperBoRG) data set together representing factor ∼1.12× larger than existing space-based sets. Using near-infrared (NIR) color cuts careful photo- analyses, we find...
Abstract We analyze new JWST NIRCam and NIRSpec data on the redshift 9.11 galaxy MACS1149-JD1 (hereafter JD1). Our imaging reveal that JD1 comprises three spatially distinct components. spectroscopic indicate appears dust free but is already enriched, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>12</mml:mn> <mml:mo>+</mml:mo> <mml:mi>log</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi mathvariant="normal">O</mml:mi> <mml:mrow>...
JWST observations of high redshift galaxies are used to measure their star formation histories - the buildup stellar mass in earliest galaxies. Here we use a novel analysis program, SEDz*, compare near-IR spectral energy distributions for with redshifts 5 < z 7 combinations population templates evolved from = 12. We exploit NIRCam imaging wide bands covering 1-5 mu m, taken context GLASS-JWST-ERS and SEDz* solve well-constrained 24 exemplary In this first look find variety histories, long,...
We use weak gravitational lensing to measure the masses of five galaxy clusters selected from South Pole Telescope (SPT) survey, with primary goal comparing these SPT Sunyaev--Zel'dovich (SZ) and X-ray based mass estimates. The span redshifts 0.28 < z 0.43 have M_500 > 2 x 10^14 h^-1 M_sun, three were discovered by survey. observed in g'r'i' passbands Megacam imager on Magellan Clay 6.5m telescope. a mean ratio (WL) aperture inferred SZ data, both within an R_500,SZ derived mass, 1.04 +/-...
ABSTRACT We measure the size–luminosity relation of photometrically selected galaxies within redshift range z ∼ 6–9, using lensed by six foreground Hubble Frontier Fields (HFF) clusters. The power afforded strong gravitational lensing allows us to observe fainter and smaller than in blank fields. select our sample obtain their properties, e.g. redshift, magnitude, from derived ASTRODEEP catalogues. intrinsic size is measured with Lenstruction software, completeness maps are created as a...
Abstract Wide Field Slitless Spectroscopy (WFSS) provides a powerful tool for detecting strong line emission in star-forming galaxies (SFGs) without the need target preselection. As part of GLASS-JWST Early Release Science (ERS) program, we leverage near-infrared wavelength capabilities NIRISS (1–2.2 μ m) to observe rest-optical lines out z ∼ 3.4, depth and with spatial resolution higher than ever before (H α < 2.4; [O iii ]+H β 3.4). In this Letter constrain rest-frame III ] λ 5007...
Abstract We present a first look at the reddest 2–5 μ m sources found in deep images from GLASS Early Release Science program. undertake general search, i.e., not looking for any particular spectral signatures, detected only bands redder than is reachable with Hubble Space Telescope, and which would likely have been identified pre-JWST surveys. search down to AB ∼27 (corresponding >10 σ detection threshold) of F200W F444W filters, >1 magnitude excess relative F090W F150W bands. Fainter...