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A&A
Volume 669, January 2023
Article Number L8
Number of page(s) 7
Section Letters to the Editor
DOI https://doi.org/10.1051/0004-6361/202244831
Published online 10 January 2023

© The Authors 2023

Licence Creative CommonsOpen Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

This article is published in open access under the Subscribe-to-Open model. Subscribe to A&A to support open access publication.

1. Introduction

One of the main science goals of the James Webb Space Telescope (JWST) is to detect the very first galaxies that formed after the Big Bang. Making use of the public release of the first JWST observations, a number of papers have reported new z > 10 galaxy candidates based on spectral energy distribution (SED) fitting of JWST near-infrared photometry (Adams et al. 2022; Atek et al. 2022; Bouwens et al. 2022; Bradley et al. 2022; Castellano et al. 2022; Donnan et al. 2023; Harikane et al. 2022a; Hsiao et al. 2022; Finkelstein et al. 2022a; Labbe et al. 2022; Naidu et al. 2022a,b; Yan et al. 2023; Finkelstein et al. 2022b; Rodighiero et al. 2023).

The highest-redshift spectroscopically confirmed galaxy prior to the launch of JWST was GN-z11 at z = 10.957 (Oesch et al. 2016; Jiang et al. 2021), with a reported UV luminosity of MUV = −22.1 ± 0.2. Recently, Harikane et al. (2022b) presented a tentative 3.8σ detection of the [O III] 88 μm emission line of a z = 13.27 galaxy candidate with a UV luminosity of MUV = −23.3 (called HD1; though Kaasinen et al. (2022) argue through statistical tests that this detection is fully consistent with being a noise fluctuation). The number density of these two bright z > 10 (candidate) galaxies is already higher than expected from theoretical models (e.g. Yung et al. 2019; Behroozi et al. 2020). A spectroscopic confirmation of the high redshift of the newly reported bright JWST z > 10 candidates is thus crucial to provide further robust constraints for galaxy formation models and further our understanding of the buildup of the very first galaxies in our Universe (Ferrara et al. 2022; Inayoshi et al. 2022; Liu & Bromm 2022; Lovell et al. 2023; Mason et al. 2022; Boylan-Kolchin 2022; Mirocha & Furlanetto 2023). Curtis-Lake et al. (2022) recently presented spectroscopic redshift confirmation of four galaxies at z = 10.45 to 13.2, with UV magnitudes in the range between −18.2 and −19.3, based on JWST/NIRSpec spectroscopy.

If all reported JWST high-redshift UV-bright candidates are indeed at z > 10, this would imply little to no evolution in the UV luminosity function of galaxies from z = 8 to z = 12 (e.g. Naidu et al. 2022a, see also Bowler et al. 2020) and highly efficient star formation within the first few 100 Myrs after the Big Bang. Spectroscopic confirmation of their redshift is necessary, since high redshift candidates classified based on near-infrared (NIR) photometry alone may also be dusty star-forming galaxies (DSFGs, e.g. Zavala et al. 2022) or quenched galaxies at z = 3 − 6 (see the alternate solution for HD1 in Harikane et al. 2022b).

One particularly exciting z > 10 candidate was recently reported by Castellano et al. (2022) and Naidu et al. (2022a). This galaxy was observed as part of the GLASS-JWST Early Release Science programme (Treu et al. 2022) and is dubbed GLASS-z13 in this paper. Independent spectral energy distribution (SED) fitting of the Lyman-alpha break of this source based on JWST/NIRCam photometry from approximately 1 to 5 μm by Castellano et al. (2022) and Naidu et al. (2022a) places this galaxy at z ≈ 12 − 13, with a UV luminosity of MUV = −21.0 ± .1. Naidu et al. (2022a) and Santini et al. (2022) performed SED fitting to the available photometry for GLASS-z13 and found a stellar mass of and and a star formation rate (SFR) of and , respectively. These differences may be caused by the use of different SED fitting codes. A further relevant systematic uncertainty on the derived properties, including the photometric redshift of GLASS-z13, is the uncertainty in the zero point of the NIRCam flux calibration (e.g. see Sect. 2.2 in Adams et al. 2022). Spectroscopic confirmation is thus necessary to overcome the uncertainties on the photometric redshift.

In this paper I present publicly available Atacama Large Millimeter/submillimeter Array (ALMA) band 6 data taken as part of a recently approved Director’s Discretionary Time (DDT) programme (2021.A.00020.S; PI: T. Bakx). The observations were targeted towards GLASS-z13 with the aim of detecting the [O III] 88 μm emission line to obtain a robust spectroscopic redshift for GLASS-z13. This strategy has successfully been adopted in the last years to obtain spectroscopic redshifts of z ∼ 9 galaxies (e.g. Laporte et al. 2017, 2021; Hashimoto et al. 2018; Tamura et al. 2019) and it has recently been used to search for [O III] 88 μm emission from various other JWST-selected z > 10 galaxy candidates (Yoon et al. 2022; Fujimoto et al. 2022). A similar analysis on GLASS-z13 is furthermore presented in Bakx et al. (2023). In Sect. 2 I present the ALMA data. I present the data analysis in Sect. 3 and discuss the findings in Sect. 4. A summary of the results is presented in Sect. 5. Throughout this Paper I use a flat Λ-CDM concordance model (H0= 70.0 km s−1 Mpc−1 and ΩM = 0.30).

2. ALMA observations and data reduction

In this paper I use publicly available ALMA band 6 data obtained as part of project 2021.A.00020.S (PI: T. Bakx) on August 3, 4, and 5, 2022, in configuration C-5. The water vapour during the observations was in the range PWV = 0.5–1 mm. The data cover a contiguous frequency range from 233.41 GHz to 263.05 GHz with a spectral resolution of 7812.01 kHz. This frequency coverage corresponds to [O III] 88 μm emission at redshifts from z = 11.9 to z = 13.5.

I make use of calibrated measurement sets restored using the Common Astronomy Software Applications (CASA, McMullin et al. 2007 version 6.2.1) package calibration scripts provided by the ALMA observatory. A spectral cube covering the entire frequency range of the observations was generated with the tclean task with a spectral resolution of 20 MHz (corresponding to ∼25 km s−1 for a typical rest frequency of 250 GHz) and applying Briggs weighting with robust parameter equals two (natural weighting). The resulting cube has a beam size of 0.39 arcsec × 0.34 arcsec and a typical noise level of 0.15 mJy/ 20 MHz/ beam. The same weighting parameters were used to create a 1.2 mm band 6 continuum image of GLASS-z13, resulting in a beam size of 0.34 arcsec × 0.31 arcsec and a typical noise level of 3.6 μJy per beam. I furthermore present a uv-tapered cube (with a taper of 0.6 arcsec) and image with a beam size of 0.8 arcsec to potentially identify low-surface brightness emission missed in the images with a smaller beam. The results discussed in this paper are qualitatively the same between the images created with the various weighting choices.

3. No [O III] 88 μm or 1.2 mm continuum emission detection

The aim of this paper is to search for [O III] 88 μm emission associated with GLASS-z13. I obtain an ALMA flux density spectrum by extracting the flux density along the frequency axis within a circular aperture with a diameter of 0.5 arcsec around the expected position of GLASS-z13 based on the JWST/NIRCam photometry. This diameter corresponds to approximately 1.25 times the beam size of the observations and a physical scale larger than the NIR half-light radius derived for GLASS-z13 of 0.5 kpc (Naidu et al. 2022a). The noise level for this aperture was estimated from the non-primary beam-corrected cube, by taking the standard deviation of the flux density in 100 apertures of the same size and offset randomly from the source position for every individual channel. The resulting integrated aperture flux density spectrum is presented in the top panel of Fig. 1. No emission line is visible in this spectrum. This conclusion is robust against changes in the aperture diameter between 0.4 and 1.0 arcsec and the re-binning of the data to 40 MHz per channel (∼50 km s−1). I did not find an emission line in the spectrum extracted from the uv-tapered cube either (see Fig. A.1). These results are consistent with the findings by Bakx et al. (2023), who did not find [O III] 88 μm line emission at the location of GLASS-z13 either.

thumbnail Fig. 1.

Top row: ALMA spectrum of GLASS-z13. The spectrum was created by extracting the flux density within a circular aperture with a diameter of 0.5 arcsec around GLASS-z13. The orange bars indicate the spectrum, whereas the grey dashed lines correspond to the 1-σ noise limit of the data. No emission line is detected within the spectrum. Bottom row: 3–σ limit on the [O III] 88 μm luminosity of GLASS-z13 as a function of redshift if GLASS-z13 is actually at z ≈ 12 − 13, but its [O III] 88 μm luminosity is too faint to have been detected by ALMA. The upper limit on the [O III] 88 μm emission was calculated assuming a line width of 100 km s−1, by taking the integrated noise within a window of width 100 km s−1 around the frequency of interest.

I used the Findclump algorithm (Walter et al. 2016) that was designed to identify emission lines in an automated fashion to search for a line using a more objective approach. The algorithm was set up to search for lines in kernels of three up to 19 channels, cropping those sources with a signal-to-noise ratio larger than three that fall within 1 arcsec and 0.4 GHz (corresponding to ∼500 km s−1) of each other. The fidelity of the detected lines (with a probability of the line being real) was estimated by comparing the number of positive lines to the number of negative lines with a signal-to-noise ratio of at least three (see Walter et al. 2016 for a description). No reliable emission line was detected within 10 arcsec of the location of GLASS-z13. This is in agreement with the findings based on Fig. 1. No emission line was detected in the uv-tapered cube either. The lack of detected [O III] 88 μm emission suggests that no [O III] 88 μm emission line is present in the explored frequency range, or it is fainter than the sensitivity limit of the data.

Bakx et al. (2023) report a tentative ∼5σ extended detection approximately 0.5″ offset from the location of GLASS-z13. Findclump identifies this line, but assigns it a fidelity of only 0.04 (with a probability of the line being real of 4%).

In the bottom panel of Fig. 1, I show the upper limit that can be derived on the [O III] 88 μm luminosity, assuming that GLASS-z13 is at z ≈ 12 − 13 and that the [O III] 88 μm emission line falls in the frequency range covered by the observations. I adopted a line width for the [O III] 88 μm emission of 100 km s−1, similar to [O III] 88 μm line widths reported for z ∼ 8 − 9 galaxies (Hashimoto et al. 2018; Tamura et al. 2019). For a channel width of 25 km s−1 (dividing the [O III] 88 μm emission over four channels), the 3-σ limit on the [O III] 88 μm line luminosity is of the order of 8 × 107 and 1 × 108 L⊙ at 240 and 260 GHz, respectively. If we instead adopt a larger line width of 400 km s−1 (see for example Hashimoto et al. 2019 and Wong et al. 2022), the 3-σ upper limit increases by a factor of two, up to 2 × 108 L⊙ at 260 GHz.

In Fig. 2 I present the ALMA 1.2 mm continuum image around GLASS-z13. No 1.2 mm continuum emission associated with GLASS-z13 is visible and hence a 3-σ upper limit of 10.8 μJy can be placed. I did not find 1.2 mm continuum emission associated with GLASS-z13 in the uv-tapered continuum map either (Fig. A.2).

thumbnail Fig. 2.

5″× 5″ cutout of the ALMA 1.2 mm continuum map around GLASS-z13. Contours indicate the −3, −2, −1, 1, 2, and 3-σ levels. The beam of the ALMA 1.2 mm image is indicated with the grey ellipse in the bottom left corner. The location of GLASS-z13 is indicated with a white cross. No continuum emission is detected at the location of GLASS-z13.

4. Discussion

The non-detection of [O III] 88 μm and 1.2 mm dust-continuum emission associated with GLASS-z13 can be explained by three scenarios that are discussed in the subsections below.

4.1. GLASS-z13 is a z ≈ 12 − 13 galaxy with an [O III] 88 μm luminosity below the sensitivity limit of the ALMA data

The first scenario to explain the non-detection of [O III] 88 μm emission is that the line does fall in the frequency range covered by the observations, but it is too faint to have been detected. To put this scenario in context, in the left panel of Fig. 3, I compare the 3-σ [O III] 88 μm limit for GLASS-z13 (∼6 × 106 L⊙; see Sect. 3) to the [O III] 88 μm luminosities measured for galaxies at z = 6 − 9 as a function of their SFR (from the compilation presented in Harikane et al. 2020). The upper limit on the [O III] 88 μm luminosity for GLASS-z13 is consistent with the empirical relation between the [O III] 88 μm luminosity and SFR of galaxies (regardless of the SFR taken for GLASS-z13).

thumbnail Fig. 3.

Left: Upper limit on the [O III] 88 μm luminosity of GLASS-z13 as a function of its SFR, compared to galaxies at z = 6 − 10 taken from the literature compilation by Harikane et al. (2020). Upper limits are presented for the two respective SFRs derived by Castellano et al. (2022) and Santini et al. (2022). If GLASS-z13 is a z > 11.9 galaxy, the upper limits are consistent with the empirical trend. Right: CLOUDY calculation results taken from Harikane et al. (2020) for the ratio between [O III] 88 μm luminosity and SFR, as a function of ionisation parameter Uion, as well as the ISM metallicity and density. Under the assumption that GLASS-z13 is a z ≈ 12 − 13 galaxy, the upper limits on the [O III] 88 μm luminosity–SFR ratio that would be obtained for the two SFRs derived in the literature are indicated by the dashed black and grey lines with arrows. A broader line width of ∼400 km s−1 would move the upper limits up by a factor of two. These upper limits suggest either a low-metallicity (< 0.2 Z⊙) and/or a dense (at least 100 cm−3) ISM.

Harikane et al. (2020) explored the ratio between the [O III] 88 μm line luminosity of galaxies and their SFR as a function of gas-phase metallicity, density, and ionisation parameter Uion using CLOUDY (Ferland et al. 2017) modelling. In the right panel of Fig. 3, I compare the upper limit on the [O III] 88 μm luminosity–SFR ratio to the model predictions taken from Harikane et al. (2020). If GLASS-13 is at z ≈ 12 − 13, the upper limit on the [O III] 88 μm luminosity–SFR ratio can be explained by low-metallicity gas (∼0.2 Z⊙ or lower). A metallicity of 0.2 Z⊙ or less is fully consistent with recent model predictions for the gas-phase metallicity of z = 12 − 13 galaxies with a stellar mass of ∼109 M⊙ (Wilkins et al. 2017; Ucci et al. 2023). A dense interstellar medium (ISM) of 103 cm−3 or possibly even higher provides an alternative explanation for the non-detection of [O III] 88 μm emission (even in combination with a solar-metallicity ISM). Indeed, Jiang et al. (2021) derived a density for GN-z11 (a z ∼ 11 spectroscopically confirmed galaxy) of at least 104 cm−3, based on ionised-carbon line ratios. If GLASS-z13 has a similar density, the non-detection of [O III] 88 μm emission is to be expected, regardless of the metallicity of the ISM. A future approach to break the degeneracy between density and metallicity is to either obtain a density tracer from ionisation lines (following e.g. Jiang et al. 2021), or by constraining the ISM metallicity and density through a detection or upper limit on [O III] 52 μm emission (following, for example, the approach outlined in Yang et al. 2021).

Binggeli et al. (2021) recently presented an empirical relation between the [O III] 88 μm-to-UV luminosity ratio and gas-phase metallicity of galaxies at z > 6. Adopting a 3-σ upper limit on the [O III] 88 μm emission from GLASS-z13 of 1 × 108 L⊙ and taking a UV magnitude of −21.0 (Naidu et al. 2022a), I find an upper limit on the [O III] 88 μm-to-UV luminosity ratio of 10−2.73. Following Binggeli et al. (2021; their Fig. 6), this is consistent with an upper limit on the oxygen abundance of approximately one-third solar (this conclusions remains qualitatively the same when adopting a line width of 400 rather than 100 km s−1). These results agree with the hypothesis of a low-metallicity ISM based on the comparison of the [O III] 88 μm luminosity–SFR ratio to CLOUDY modelling predictions.

Future JWST/NIRSpec spectroscopy will be able to confirm or reject the tentative high redshift of GLASS-z13. If GLASS-z13 indeed has a redshift of z ≈ 12 − 13, the upper limit on its [O III] 88 μm line emission may imply that GLASS-z13 has a low metallicity and/or dense ISM. This shows that even an ALMA [O III] 88 μm non-detection may provide unique insights into the ISM properties and star formation history of the first galaxies that formed in our Universe.

4.2. GLASS-z13 is a z = 4–5 DSFG or quenched galaxy

The second scenario to explain the non-detection of [O III] 88 μm emission is that GLASS-z13 is a z ≈ 3 quenched or z ≈ 4 − 6 DSFG. The drop in the JWST/NIRCam photometry between F150W and F200W (see Castellano et al. 2022; Naidu et al. 2022a) is then either driven by strong dust obscuration of UV emission from a z ≈ 4 − 6 DSFG, or by the 4000 Å break of a z ∼ 3 quenched galaxy.

Zavala et al. (2022) recently presented 1.1 mm Northern Extended Millimeter Array (NOEMA) observations of a z > 17 JWST galaxy candidate. They demonstrated that with the inclusion of the 1.1 mm continuum emission, the SED fit of this z ∼ 17 candidate is more consistent with a z ∼ 5 DSFG than a z > 17 solution. The stringent 3-σ upper limit on the 1.2 mm continuum emission (which at z ≈ 4 − 6 would be close to the peak of the far-infrared SED) suggests that GLASS-z13 is unlikely a DSFG. Indeed, the 3-σ upper limit at 1.2 mm corresponds to a total IR luminosity of 1.52 × 1010 L⊙ for a galaxy at z = 4 (assuming a dust temperature of 35 K) and an upper limit on the SFR of only 2.25 M⊙ yr−1 (following Kennicutt & Evans 2012).

Naidu et al. (2022a) explored the possibility of GLASS-z13 being a low-redshift galaxy by forcing a z < 6 best-fit SED solution using the EaZy SED-fitting code (Brammer et al. 2008). They found that the JWST/NIRCam photometry can best be described by a z ≈ 3 quenched galaxy with a stellar mass of 108 − 9 M⊙ when adopting the z < 6 constraint. This solution is however unlikely since, based on this solution, one would expect a > 5σ detection in the F150W band where no flux is present (see Fig. 1 in Naidu et al. 2022a). Future JWST/NIRSpec spectroscopy may be able to robustly confirm or rule out a z ≈ 3 − 6 galaxy solution, while also accounting for the uncertainty in the zero point of the NIRCam flux calibration.

4.3. GLASS-z13 has a high redshift outside of the frequency range covered

A third explanation for the lack of detected [O III] 88 μm emission is that GLASS-z13 is actually at a redshift z > 11, but outside of the frequency range covered by the ALMA data presented. SED fitting of the JWST/NIRCam photometry with Prospector (Leja et al. 2017, 2019; Johnson et al. 2021) by Naidu et al. (2022a) shows that a redshift between z = 13.5 and z = 15 is also a possible solution. However, this solution is in disagreement with the results from the EaZy (Brammer et al. 2008) and zphot (Fontana et al. 2000) fitting codes (see Naidu et al. 2022a; Castellano et al. 2022).

5. Summary

In this paper I have presented publicly available ALMA band 6 DDT observations (2021.A.00020.S, PI: T. Bakx) of GLASS-z13, a z ≈ 12 − 13 galaxy candidate based on SED fitting of JWST/NIRCam photometry from 1 to 5 μm. The observations were designed to acquire a spectroscopic redshift for GLASS-z13, by searching for [O III] 88 μm emission in a contiguous frequency range corresponding to [O III] 88 μm emission at redshifts 11.9 to 13.5. The main results include:

  • No [O III] 88 μm emission line associated with GLASS-z13 (nor in its vicinity) is detected in the frequency range corresponding to redshifts 11.9 to 13.5, nor is continuum emission at 1.2 mm detected.

  • The lack of detected [O III] 88 μm emission associated with GLASS-z13 can be explained by three scenarios:

    • 1. GLASS-z13 is at z ≈ 12 − 13, but has an [O III] 88 μm luminosity fainter than the noise limit of the data presented in this work.

    • 2. GLASS-z13 is a z ≈ 3 low-mass quenched galaxy; although, the SED expected for such a galaxy is in disagreement with the JWST/NIRCam photometry (Naidu et al. 2022a). Alternatively, it may be a z ≈ 4 − 6 DSFG; although, the stringent 1.2 mm continuum upper limit appears to rule this scenario out as well.

    • 3. GLASS-z13 has a redshift in the range z = 13.5 − 15, which is in agreement with the redshift solution of the Prospector SED fitting code, but this has been ruled out by the zphot and EaZy codes (see Naidu et al. 2022a).

  • If GLASS-z13 is at z ≈ 12 − 13, the [O III] 88 μm upper limit of 1 × 108 L⊙ can be explained by a low-metallicity (∼0.2 Z⊙) and/or dense (> 100 cm−3 or higher) ISM. A low metallicity is consistent with recent model predictions for the metallicity of galaxies at z = 12 − 13 (Wilkins et al. 2017; Ucci et al. 2023) and an empirical relation between the [O III] 88 μm-to-UV luminosity ratio and oxygen abundance of Binggeli et al. (2021).

The non-detection of the [O III] 88 μm emission line makes it currently impossible to confirm or reject the z ≈ 12 − 13 photometric redshift of GLASS-z13. JWST/NIRSpec spectroscopy will be necessary for a definite confirmation or rejection. If GLASS-z13 is at z ≈ 12 − 13, the presented ALMA observations provide new insights into the ISM properties of galaxies at z ≈ 12 − 13. This demonstrates the tremendous synergy between JWST and ALMA to study the existence and properties of the first galaxies to have formed in our Universe.

Acknowledgments

I thank Tony Mroczkowski and Michele Ginolfi for useful discussions and Tom Bakx for noticing an error in an earlier version of the paper. I thank the referee, Akio Inoue, for a constructive report. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2021.A.00020.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. I made use of the following software packages: matplotlib (Hunter 2007), numpy (Harris et al. 2020), scipy (Virtanen et al. 2020), jupyter (Kluyver et al. 2016), Astropy (Astropy Collaboration 2018), interferopy (Boogaard et al. 2021) and CARTA (Comrie et al. 2021). This paper made use of calibrated measurement sets provided by the European ALMA Regional Centre network (Hatziminaoglou et al. 2015) through the calMS service (Petry et al. 2020).

References

  1. Adams, N. J., Conselice, C. J., Ferreira, L., et al. 2022, MNRAS, 518, 4755 [NASA ADS] [CrossRef] [Google Scholar]
  2. Astropy Collaboration (Price-Whelan, A. M., et al.) 2018, AJ, 156, 123 [Google Scholar]
  3. Atek, H., Shuntov, M., Furtak, L. J., et al. 2022, MNRAS, submitted [arXiv:2207.12338] [Google Scholar]
  4. Bakx, T. J. L. C., Zavala, J. A., Mitsuhashi, I., et al. 2023, MNRAS, 519, 1201 [Google Scholar]
  5. Behroozi, P., Conroy, C., Wechsler, R. H., et al. 2020, MNRAS, 499, 5702 [NASA ADS] [CrossRef] [Google Scholar]
  6. Binggeli, C., Inoue, A. K., Hashimoto, T., et al. 2021, A&A, 646, A26 [NASA ADS] [CrossRef] [EDP Sciences] [Google Scholar]
  7. Boogaard, L., Meyer, R. A., & Novak, M. 2021, https://doi.org/10.5281/zenodo.5775603 [Google Scholar]
  8. Bouwens, R. J., Stefanon, M., Brammer, G., et al. 2022, MNRAS, submitted [arXiv:2211.02607] [Google Scholar]
  9. Bowler, R. A. A., Jarvis, M. J., Dunlop, J. S., et al. 2020, MNRAS, 493, 2059 [Google Scholar]
  10. Boylan-Kolchin, M. 2022, MNRAS, submitted [arXiv:2208.01611] [Google Scholar]
  11. Bradley, L. D., Coe, D., Brammer, G., et al. 2022, ApJ, submitted [arXiv:2210.01777] [Google Scholar]
  12. Brammer, G. B., van Dokkum, P. G., & Coppi, P. 2008, ApJ, 686, 1503 [Google Scholar]
  13. Castellano, M., Fontana, A., Treu, T., et al. 2022, ApJ, 938, L15 [NASA ADS] [CrossRef] [Google Scholar]
  14. Comrie, A., Wang, K. S., Hsu, S. C., et al. 2021, https://doi.org/10.5281/zenodo.3377984 [Google Scholar]
  15. Curtis-Lake, E., Carniani, S., Cameron, A., et al. 2022, ArXiv e-prints [arXiv:2212.04568] [Google Scholar]
  16. Donnan, C. T., McLeod, D. J., Dunlop, J. S., et al. 2023, MNRAS, 518, 6011 [Google Scholar]
  17. Ferland, G. J., Chatzikos, M., Guzmán, F., et al. 2017, Rev. Mex. Astron. Astrofis., 53, 385 [NASA ADS] [Google Scholar]
  18. Ferrara, A., Pallottini, A., & Dayal, P. 2022, ArXiv e-prints [arXiv:2208.00720] [Google Scholar]
  19. Finkelstein, S. L., Bagley, M. B., Arrabal Haro, P., et al. 2022a, ApJ, 940, L55 [NASA ADS] [CrossRef] [Google Scholar]
  20. Finkelstein, S. L., Bagley, M. B., Ferguson, H. C., et al. 2022b, ApJ, submitted [arXiv:2211.05792] [Google Scholar]
  21. Fontana, A., D’Odorico, S., Poli, F., et al. 2000, AJ, 120, 2206 [NASA ADS] [CrossRef] [Google Scholar]
  22. Fujimoto, S., Finkelstein, S. L., Burgarella, D., et al. 2022, ApJ, submitted [arXiv:2211.03896] [Google Scholar]
  23. Harikane, Y., Ouchi, M., Inoue, A. K., et al. 2020, ApJ, 896, 93 [Google Scholar]
  24. Harikane, Y., Ouchi, M., Oguri, M., et al. 2022a, ApJ, submitted [arXiv:2208.01612] [Google Scholar]
  25. Harikane, Y., Inoue, A. K., Mawatari, K., et al. 2022b, ApJ, 929, 1 [NASA ADS] [CrossRef] [Google Scholar]
  26. Harris, C. R., Millman, K. J., van der Walt, S. J., et al. 2020, Nature, 585, 357 [Google Scholar]
  27. Hashimoto, T., Laporte, N., Mawatari, K., et al. 2018, Nature, 557, 392 [NASA ADS] [CrossRef] [Google Scholar]
  28. Hashimoto, T., Inoue, A. K., Mawatari, K., et al. 2019, PASJ, 71, 71 [Google Scholar]
  29. Hatziminaoglou, E., Zwaan, M., Andreani, P., et al. 2015, The Messenger, 162, 24 [NASA ADS] [Google Scholar]
  30. Hsiao, T. Y.-Y., Coe, D., Abdurro’uf, et al. 2022, Nature, submitted [arXiv:2210.14123] [Google Scholar]
  31. Hunter, J. D. 2007, Comput. Sci. Eng., 9, 90 [Google Scholar]
  32. Inayoshi, K., Harikane, Y., Inoue, A. K., Li, W., & Ho, L. C. 2022, ApJ, 938, L10 [NASA ADS] [CrossRef] [Google Scholar]
  33. Jiang, L., Kashikawa, N., Wang, S., et al. 2021, Nat. Astron., 5, 256 [NASA ADS] [CrossRef] [Google Scholar]
  34. Johnson, B. D., Leja, J., Conroy, C., & Speagle, J. S. 2021, ApJS, 254, 22 [NASA ADS] [CrossRef] [Google Scholar]
  35. Kaasinen, M., van Marrewijk, J., Popping, G., et al. 2022, A&A, submitted [arXiv:2210.03754] [Google Scholar]
  36. Kennicutt, R. C., & Evans, N. J. 2012, ARA&A, 50, 531 [NASA ADS] [CrossRef] [Google Scholar]
  37. Kluyver, T., Ragan-Kelley, B., Pérez, F., et al. 2016, Jupyter Notebooks - a Publishing Format for Reproducible Computational Workflows (IOS Press), 87 [Google Scholar]
  38. Labbe, I., van Dokkum, P., Nelson, E., et al. 2022, Nature, submitted [arXiv:2207.12446] [Google Scholar]
  39. Laporte, N., Ellis, R. S., Boone, F., et al. 2017, ApJ, 837, L21 [CrossRef] [Google Scholar]
  40. Laporte, N., Meyer, R. A., Ellis, R. S., et al. 2021, MNRAS, 505, 3336 [NASA ADS] [CrossRef] [Google Scholar]
  41. Leja, J., Johnson, B. D., Conroy, C., van Dokkum, P. G., & Byler, N. 2017, ApJ, 837, 170 [NASA ADS] [CrossRef] [Google Scholar]
  42. Leja, J., Carnall, A. C., Johnson, B. D., Conroy, C., & Speagle, J. S. 2019, ApJ, 876, 3 [Google Scholar]
  43. Liu, B., & Bromm, V. 2022, ApJ, 937, L30 [NASA ADS] [CrossRef] [Google Scholar]
  44. Lovell, C. C., Harrison, I., Harikane, Y., Tacchella, S., & Wilkins, S. M. 2023, MNRAS, 518, 2511 [Google Scholar]
  45. Mason, C. A., Trenti, M., & Treu, T. 2022, MNRAS, submitted [arXiv:2207.14808] [Google Scholar]
  46. McMullin, J. P., Waters, B., Schiebel, D., Young, W., & Golap, K. 2007, in Astronomical Data Analysis Software and Systems XVI, eds. R. A. Shaw, F. Hill, & D. J. Bell, ASP Conf. Ser., 376, 127 [Google Scholar]
  47. Mirocha, J., & Furlanetto, S. R. 2023, MNRAS, 519, 843 [Google Scholar]
  48. Naidu, R. P., Oesch, P. A., Dokkum, P.V., et al. 2022a, ApJ, 940, L14 [NASA ADS] [CrossRef] [Google Scholar]
  49. Naidu, R. P., Oesch, P. A., Setton, D. J., et al. 2022b, ApJ, submitted [arXiv:2208.02794] [Google Scholar]
  50. Oesch, P. A., Brammer, G., van Dokkum, P. G., et al. 2016, ApJ, 819, 129 [NASA ADS] [CrossRef] [Google Scholar]
  51. Petry, D., Stanke, T., Biggs, A., et al. 2020, The Messenger, 181, 16 [NASA ADS] [Google Scholar]
  52. Rodighiero, G., Bisigello, L., Iani, E., et al. 2023, MNRAS, 518, L19 [Google Scholar]
  53. Santini, P., Fontana, A., Castellano, M., et al. 2022, ApJ, submitted [arXiv:2207.11379] [Google Scholar]
  54. Tamura, Y., Mawatari, K., Hashimoto, T., et al. 2019, ApJ, 874, 27 [NASA ADS] [CrossRef] [Google Scholar]
  55. Treu, T., Roberts-Borsani, G., Bradac, M., et al. 2022, ApJ, 935, 110 [NASA ADS] [CrossRef] [Google Scholar]
  56. Ucci, G., Dayal, P., Hutter, A., et al. 2023, MNRAS, 518, 3557 [Google Scholar]
  57. Virtanen, P., Gommers, R., Oliphant, T. E., et al. 2020, Nat. Methods, 17, 261 [Google Scholar]
  58. Walter, F., Decarli, R., Aravena, M., et al. 2016, ApJ, 833, 67 [Google Scholar]
  59. Wilkins, S. M., Feng, Y., Di Matteo, T., et al. 2017, MNRAS, 469, 2517 [NASA ADS] [CrossRef] [Google Scholar]
  60. Wong, Y. H. V., Wang, P., Hashimoto, T., et al. 2022, ApJ, 929, 161 [NASA ADS] [CrossRef] [Google Scholar]
  61. Yan, H., Ma, Z., Ling, C., et al. 2023, ApJ, 942, L9 [NASA ADS] [CrossRef] [Google Scholar]
  62. Yang, S., Lidz, A., & Popping, G. 2021, MNRAS, 504, 723 [NASA ADS] [CrossRef] [Google Scholar]
  63. Yoon, I., Carilli, C. L., Fujimoto, S., et al. 2022, ApJ, submitted [arXiv:2210.08413] [Google Scholar]
  64. Yung, L. Y. A., Somerville, R. S., Finkelstein, S. L., Popping, G., & Davé, R. 2019, MNRAS, 483, 2983 [NASA ADS] [CrossRef] [Google Scholar]
  65. Zavala, J. A., Buat, V., Casey, C. M., et al. 2022, ApJ, submitted [arXiv:2208.01816] [Google Scholar]

Appendix A: uv-tapered images

In Figure A.1 I show the integrated flux density spectrum of GLASS-z13 within an aperture with a diameter of 1 arcsec extracted from the uv-tapered cube. An aperture of 1 arcsec is slightly larger than the beam size of 0.8 arcsec of the uv-tapered image. No emission line is visible in this spectrum. An automated-line finding using Findclump does not reveal any reliabl emission line within 10 arcsec of the location of GLASS-z13 either. These results are consistent with the results discussed in the main body of this work.

thumbnail Fig. A.1.

ALMA spectrum of GLASS-z13, extracted from the uv-tapered cube (with a taper of 0.6 arcsec). The spectrum was created by extracting the flux density within a circular aperture with a diameter of 1 arcsec around GLASS-z13. The orange bars indicate the spectrum, whereas the grey dashed lines correspond to the 1-σ noise limit of the data. No emission line is detected within the spectrum.

I present the uv-tapered 1.2 mm continuum map around GLASS-z13 in Figure A.2. No 1.2 mm continuum emission is visible in this image, which is in agreement with the results discussed in the main body of this work.

thumbnail Fig. A.2.

8″ × 8″ cutout of the ALMA uv-tapered 1.2 mm continuum map around GLASS-z13 (with a taper of 0.6 arcsec). Contours indicate the -3, -2, -1, 1, 2, and 3 σ levels. The beam of the ALMA 1.2 mm image is indicated with the grey ellipse in the bottom left corner, whereas the location of GLASS-z13 is indicated with a white cross. No continuum emission is detected at the location of GLASS-z13 in the uv-tapered image.

All Figures

thumbnail Fig. 1.

Top row: ALMA spectrum of GLASS-z13. The spectrum was created by extracting the flux density within a circular aperture with a diameter of 0.5 arcsec around GLASS-z13. The orange bars indicate the spectrum, whereas the grey dashed lines correspond to the 1-σ noise limit of the data. No emission line is detected within the spectrum. Bottom row: 3–σ limit on the [O III] 88 μm luminosity of GLASS-z13 as a function of redshift if GLASS-z13 is actually at z ≈ 12 − 13, but its [O III] 88 μm luminosity is too faint to have been detected by ALMA. The upper limit on the [O III] 88 μm emission was calculated assuming a line width of 100 km s−1, by taking the integrated noise within a window of width 100 km s−1 around the frequency of interest.
In the text
thumbnail Fig. 2.

5″× 5″ cutout of the ALMA 1.2 mm continuum map around GLASS-z13. Contours indicate the −3, −2, −1, 1, 2, and 3-σ levels. The beam of the ALMA 1.2 mm image is indicated with the grey ellipse in the bottom left corner. The location of GLASS-z13 is indicated with a white cross. No continuum emission is detected at the location of GLASS-z13.
In the text
thumbnail Fig. 3.

Left: Upper limit on the [O III] 88 μm luminosity of GLASS-z13 as a function of its SFR, compared to galaxies at z = 6 − 10 taken from the literature compilation by Harikane et al. (2020). Upper limits are presented for the two respective SFRs derived by Castellano et al. (2022) and Santini et al. (2022). If GLASS-z13 is a z > 11.9 galaxy, the upper limits are consistent with the empirical trend. Right: CLOUDY calculation results taken from Harikane et al. (2020) for the ratio between [O III] 88 μm luminosity and SFR, as a function of ionisation parameter Uion, as well as the ISM metallicity and density. Under the assumption that GLASS-z13 is a z ≈ 12 − 13 galaxy, the upper limits on the [O III] 88 μm luminosity–SFR ratio that would be obtained for the two SFRs derived in the literature are indicated by the dashed black and grey lines with arrows. A broader line width of ∼400 km s−1 would move the upper limits up by a factor of two. These upper limits suggest either a low-metallicity (< 0.2 Z⊙) and/or a dense (at least 100 cm−3) ISM.
In the text
thumbnail Fig. A.1.

ALMA spectrum of GLASS-z13, extracted from the uv-tapered cube (with a taper of 0.6 arcsec). The spectrum was created by extracting the flux density within a circular aperture with a diameter of 1 arcsec around GLASS-z13. The orange bars indicate the spectrum, whereas the grey dashed lines correspond to the 1-σ noise limit of the data. No emission line is detected within the spectrum.
In the text
thumbnail Fig. A.2.

8″ × 8″ cutout of the ALMA uv-tapered 1.2 mm continuum map around GLASS-z13 (with a taper of 0.6 arcsec). Contours indicate the -3, -2, -1, 1, 2, and 3 σ levels. The beam of the ALMA 1.2 mm image is indicated with the grey ellipse in the bottom left corner, whereas the location of GLASS-z13 is indicated with a white cross. No continuum emission is detected at the location of GLASS-z13 in the uv-tapered image.
In the text

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