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REVIEW 4 major objections 5 minor 19 references

An on-sky investigation into factors limiting the performance of Keck-NIRC2 for conducting infrared high-contrast imaging

T0 review · 4 major / 5 minor · reviewed 2026-08-15 · deepseek-v4-flash

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Pith's one-line read Keck-NIRC2's gap between predicted and actual infrared sensitivity is traced to three instrument effects: the vortex coronagraph's throughput loss and added background, sky background drift faster than 30 seconds, and a rotating derotator…

desk verdict Useful on-sky numbers for NIRC2, but the 'extra coronagraph background' claim is not secure against the sky drift the paper itself measures. read the letter →

arxiv 2509.07138 v1 pith:SO54XIJ7 submitted 2025-09-08 astro-ph.IM

Rachel Bowens-Rubin , Maïssa Salama , Jayke S. Nguyen , William Thompson , Philip Hinz This is my paper · ORCID
classification astro-ph.IM
keywords high-contrastimaginginfraredKeckNIRC2vectorvortexcoronagraphskybackgrounddriftimagederotatorthroughputmeasurementexoplanet
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper tests three suspected culprits for why Keck-NIRC2 high-contrast imaging at 3–5 microns reaches only a fraction of its predicted sensitivity. On-sky measurements show the L/M vector vortex coronagraph passes only 82% of Lp light and 57% of Ms light, and it adds extra background flux that is worse in Ms. Fast-readout data reveal the sky background drifts on timescales under 30 seconds, so a 30-second exposure integrates over a moving background. The image derotator imprints a quasi-static rotating dust pattern that standard PCA background subtraction cannot remove. Together these effects account for part of the 1.7–2.0 magnitude gap between predicted and observed sensitivity limits.

What carries the argument

The central object is the vector vortex coronagraph, a diamond optic with an antireflective grating that suppresses on-axis starlight. The paper measures its throughput by moving it in and out of the beam with a star offset 1 arcsecond, comparing aperture photometry, and also compares background counts in a 100×100 pixel corner to separate throughput loss from added background. The other two mechanisms are the sky background's temporal drift, sampled at 0.01–0.05 seconds per coadd using the upgraded readout electronics, and the image derotator's quasi-static dust pattern, found by median-combining derotated frames.

What would settle it

A bench measurement of the same vortex mask at 4.6 microns under a controlled source giving about 70% throughput would show the on-sky Ms deficit (57%) comes from telescope-state differences rather than the optic itself; alternatively, repeating the on-sky in/out test while dithering the derotator would separate the rotator pattern from the coronagraph's added background.

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Extended reading notes

Core claim

The central claim is that three instrumental effects degrade NIRC2's high-contrast sensitivity at Lp and Ms: the vortex coronagraph's throughput loss and self-emission, sub-30-second sky background drift, and a derotator-generated rotating background pattern. The paper quantifies the coronagraph's throughput and background ratios, documents background drift with sub-second coadds, and maps the derotator pattern. These findings explain part of the discrepancy between predicted and on-sky 5-sigma limits, which is 2.0 magnitudes in Lp and 1.7 magnitudes in Ms.

Load-bearing premise

The in/out comparison is assumed to isolate the coronagraph's effect, with all other optics, alignment, and readout settings held fixed; if those shifted between frames, the reported throughput and background ratios would be biased.

Editorial extensions

If this is right

  • Using the vortexlm in Ms costs more than in Lp: throughput drops from 82% to 57% while background flux ratios worsen, so Ms observations should budget for a larger sensitivity penalty.
  • Reducing exposure times to well under 30 seconds (ideally under 1 second) should improve sky-background subtraction because the sky drifts at those timescales and read noise is only 11–14 photons per pixel.
  • The derotator's rotating background pattern will not be removed by standard PCA sky subtraction, so new calibration or cleaning procedures are needed.
  • Regular cleaning of the derotator and vortex optic, plus measuring background before and after cleaning, should quantify and reduce the dust-related non-uniformity.
  • The vortex center glow adds 0.27–0.65 magnitudes of sensitivity loss at 2 lambda/D separations, affecting small inner working angle science.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the Ms throughput loss is caused by diamond absorption near 4.5–5 microns, other diamond-substrate coronagraphs on future ELT instruments may face the same wavelength-dependent penalty, so cold stops and coating choices should be tested at Ms before design freeze.
  • The sub-30-second sky drift could be exploited by a real-time background monitor: using the new high-speed coadds, observers could fit and subtract a time-varying sky level rather than a single median, potentially recovering a large fraction of the lost sensitivity.
  • The derotator's rotating pattern could be removed in post-processing if the derotator angle is recorded per frame: a de-rotation by half the drive angle before PCA would turn the pattern static, unlike current pipelines that assume a fixed sky.
  • A dedicated flat field taken with the vortex in place, combined with the derotator map, could correct the spatial non-uniformity, but the vortex center glow makes a simple flat inadequate; a two-step calibration might work.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. This paper reports on-sky tests with Keck-NIRC2 to identify factors that limit 3–5 micron high-contrast imaging. The authors measure the L/M vector vortex coronagraph throughput in Lp and Ms, compare background levels with and without the coronagraph, use the new fast-readout electronics to sample sky background at sub-second cadence, and document a quasi-static background pattern attributed to the image derotator. They conclude that the vortex coronagraph reduces throughput more in Ms (57% by aperture photometry) than in Lp (82%), that it adds background flux above the throughput penalty, that the sky background drifts on timescales shorter than 30 s, and that the derotator contributes spatial non-uniformity. The paper closes with observing recommendations, including shorter exposures and optics cleaning.

Significance. If the quantitative claims survive scrutiny, this is a useful empirical characterization for observers planning NIRC2 high-contrast imaging and for the design of future mid-infrared instruments. The direct comparison of on-sky throughput to published lab measurements, the use of the upgraded readout to probe sub-second sky variability, and the decision to place frames in the Keck Observatory Archive are clear strengths. The paper addresses a real discrepancy between predicted and on-sky sensitivity limits and its recommendations are actionable.

major comments (4)
  1. [§2.2–2.3, Table 1] The on-sky throughput and background-ratio numbers (82%, 57%, 86%, 70%) are quoted without uncertainties, and the measurement is based on a single sequence of three frames per configuration on one night. Since Section 3 demonstrates that the sky background in Lp and Ms drifts on timescales shorter than 30 s and is inconsistent with Poisson statistics, the in/out background comparison can be biased by a few percent to tens of percent. In Lp the claimed 'elevated background' is only a 4-percentage-point excess of the background ratio over the throughput ratio (86% vs 82%), well within the drift documented in Section 3; the Ms excess (70% vs 57%) could also be partly drift. Please provide uncertainty estimates, timestamps, or a control measurement that quantifies drift between the 'in' and 'out' background frames, or weaken the claim of coronagraph-added background accordingly.
  2. [§1.1 and §5] The claim that these effects explain part of the 1.7–2.0 magnitude discrepancy between predicted and on-sky sensitivity is not quantitatively connected to the measured penalties. No error budget or propagation is given that converts throughput, background ratio, drift, and derotator non-uniformity into a magnitude offset. Please add a quantitative accounting, even approximate, showing how the measured factors sum to the discrepancy, or explicitly state that the paper does not attempt this.
  3. [§3, Fig. 8, Table 2] The claim that 30 s background sequences are inconsistent with Poisson statistics is supported only by illustrative plots and a qualitative statement; no statistical test is reported. The manuscript should quantify the excess variance (e.g., variance-to-mean ratio, reduced chi-squared, or autocorrelation timescale) for the sequences in Table 2 and state how many of the 36 sequences show the effect.
  4. [§4, Fig. 10] The de-rotator dust map is descriptive: it is derived from a single median-combined de-rotated stack, with no test that the pattern rotates at the de-rotator rate, no comparison with a non-de-rotated reduction, and no estimate of its impact on contrast. Given the paper's stated goal of documenting the derotator contribution, please add a simple rotation test or explicitly mark this section as preliminary only; the conclusions currently present it as an established effect.
minor comments (5)
  1. [Throughout] The manuscript needs proofreading for typos such as 'utalize' (§1.1), 'of of' (§2.1), 'corisponding' (Fig. 8 caption), and 'hypothesis' used as a verb (§2.3).
  2. [Table 1] The row 'Measured ratio of bg counts no/withvortexlm' should state explicitly whether the ratio is (with vortex)/(without vortex) or its inverse; the current label is ambiguous.
  3. [§2.2, Fig. 3] Please state whether the aperture photometry and background measurements in Section 2.2 were performed on flat/dark-corrected frames or on raw frames, since Fig. 3 is described as 'before flat/dark corrections were applied.'
  4. [§2.2] The two throughput methods (max-pixel ratio and aperture photometry) are not equivalent because the vortex alters the PSF morphology; the paper should state which value is used in subsequent conclusions and why.
  5. [§3] For the sky background tests, please state the selection criteria for the sequences shown in Fig. 8 and report whether the remaining sequences in Table 2 show the same behavior.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: all load-bearing results are direct on-sky photometric and time-series measurements compared against external lab/published values.

full rationale

The paper's claims rest on direct measurements rather than on quantities defined in terms of the conclusions. The vortex throughput is measured by comparing aperture photometry of the same star with the vortex in and out of the optical path; the background elevation is measured by comparing mean counts in a fixed image corner with and without the vortex. These are independent observables, not derived from each other or from the claimed discrepancy. The sky-background drift claim comes from sub-second coadd time series compared against dark frames and Poisson expectations. The derotator pattern is documented by median-combining de-rotated science frames. The 1.7–2.0 mag discrepancy is taken from external prediction tools (NIRC2 SNR calculator, VICO) and published contrast curves, and the paper explicitly frames its measurements as tracing the discrepancy's causes, not as fitting it. The one self-citation to Bowens-Rubin et al. 2023 is for modified SNR equations that are not used in the analysis, so it is not load-bearing. The skeptic's concern about temporal drift between the sequential in/out frames is a legitimate measurement-robustness caveat, but it does not turn the inference into a circular one; it would be a potential systematic error, not a definitional or fit-by-construction issue.

Assumptions & free parameters 0 free parameters · 3 assumptions · 0 invented entities

The paper does not introduce free parameters or invented entities. It relies on standard observational assumptions about sky subtraction, aperture choice, and the origin of the rotating background pattern. The absence of a contaminating source and the stability of darks are supporting checks, but the assumptions above are load-bearing for the quantitative claims.

assumptions (3)
  • domain assumption Background frames taken with and without the vortex accurately represent the sky background during the corresponding PSF frames, so subtraction isolates the stellar flux.
    Used for all throughput measurements in Section 2.2; if the sky changed between frames, the measured ratios would be biased.
  • domain assumption The 0.2 arcsec aperture chosen for the sky variability analysis is representative of the background-limited regime for companion hunting.
    Section 3 uses this aperture to 'resemble the spatial scale used for companion hunting'; a different aperture could show different drift statistics.
  • domain assumption The quasi-static pattern that rotates with the derotator is caused by dust on the k-mirror and not by an artifact of the de-rotation or data processing.
    Section 4 speculates dust or optical imperfections on the de-rotator; no direct inspection or independent confirmation is provided.

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Pith. "Pith review of An on-sky investigation into factors limiting the performance of Keck-NIRC2 for conducting infrared high-contrast imaging." pith.science (2026). https://pith.science/paper/SO54XIJ7

@misc{pith2026250907138,
  author       = {Pith},
  title        = {Pith review of: An on-sky investigation into factors limiting the performance of Keck-NIRC2 for conducting infrared high-contrast imaging},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/SO54XIJ7}},
  note         = {Machine review of arXiv:2509.07138}
}
abstract

The most common instrument used by the exoplanet/brown dwarf direct imaging community at the W.M. Keck Observatory is currently the NIRC2 near-infrared imager. We performed on-sky testing to investigate three effects which may be limiting the performance of NIRC2 when conducting high-contrast imaging observations from $3-5\mu$m. First, we report the measurements of an on-sky test of the throughput of the L/M vector vortex coronagraph. We quantify the throughput and additional background flux penalties, noting that the performance effects of using the vector vortex coronagraph in the Ms-filter are greater than in the Lp-filter. Second, we utilize the recently commissioned NIRC2 electronics upgrade to measure the sky variability at sub-second speeds. We find that the background varies at timescales of less than 30s, indicating that the electronics upgrade may open an opportunity to improve the sky-background subtraction of future surveys. Third, we document the contribution of the image derotator to the spatial non-uniformity in the background flux. We conclude by giving a set of recommendations of how the Keck-NIRC2 high-contrast imaging community can adapt their observing strategies to improve the sensitivity of future surveys.

Figures

Figures reproduced from arXiv: 2509.07138 by the authors.

Figure 1
Figure 1. Keck fixhex pupil stop. The fixhex pupil stop is optimized for use with the VVC. It covers 84% of the pupil area (shown in yellow) as compared to the full size of the Keck pupil (shown in aqua). Figure Credit: Gary Ruane calculator predicts that the 5σ limit will be at a magnitude of 15.9. The published contrast curves plateau at a 5-sigma background limit of ∼ 14.2 when using the Ms filter when the vortexlm is incl… view at source ↗
Figure 2
Figure 2. Comparison of the PSF vortex-in images with Lp and Ms filters. The images have been scaled be in units of photons/second, and the sky subtraction was performed by subtracting the median background value. The stellar PSF can be seen on the left and the vortex center glow effect is seen on the right. The vortex center glow is more pronounced in the Ms filter as compared to the Lp filter. affects the exoplanet direct i… view at source ↗
Figure 3
Figure 3. Vortex on-sky throughput test. A star was intentionally miscentered from the vortex to simulate a com￾panion with a separation of 1 arcsec. The four image types were collected to measure the throughput of the vortexlm with the Lp and Ms filters. This figure shows one raw image from each of the four image types from the Ms filter before flat/dark corrections were applied. A dust pattern can be seen to be affecting th… view at source ↗
Figures from the paper (7 more)
Figure 4
Figure 4. Figure 4: Throughput measurement of the vortexlm. The comparison of the 1D cross section profiles of the stellar PSF is shown for Lp (left) and Ms (right). A star was off-centered from the coronagraph by 1 arcsec to act as a proxy for a companion in the background limited regime…
Figure 5
Figure 5. Figure 5: Spatial effects on the background due to the vortexlm. The 100 x 100 pixel zoomed in corner of the stellar PSF frames are shown for the Ms filter. Spatial non-uniformity in the background is introduced when the vortexlm is in the optical path [PITH_FULL_IMAGE:figures/…
Figure 6
Figure 6. Figure 6: Brightness of the Vortex Center Glow. The 1D cross section along the x-axis of the vortex center glow flux is plotted above in order to compare the center glow in Lp and Ms. (Left) The cross sections of the vortex center glow are shown scaled by pixel number before any…
Figure 7
Figure 7. Figure 7: Cartoon illustration of how drifts in sky background counts may cause the sky background noise to be under predicted. (Panel 1) We imagine a drift of sky background counts at a time scale of less than a typical image integration (< 30s). The dotted line represents the …
Figure 8
Figure 8. Figure 8: Sky Background Variability: Examples of 30s time sequence test from Dec 26 2023 UT. The background counts measured in each coadd are plotted with their corisponding Power Spectral Density (PSD) signal below for each time series [PITH_FULL_IMAGE:figures/full_fig_p010_8.png]
Figure 9
Figure 9. Figure 9: Photons per pixel within each coadd of a Dark Frame We see no drifting in the dark frames of either time duration (tint = 0.05s on left and tint = 0.01s on right). We measured the read noise to be similar within the two sequences (∼ 12 photons/px). 400 600 800 1000 120…
Figure 10
Figure 10. Figure 10: The Keck II AO bench de-rotator dust map. The features present are persistent throughout the observing sequence and are quasi-static, changing slightly between frames. These extended features are not present in shorter wavelength observations [PITH_FULL_IMAGE:figures…

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Works this paper leans on

19 extracted references · 17 canonical work pages

  1. [1]

    Surveying nearby brown dwarfs with HGCA: direct imaging discovery of a faint, high-mass brown dwarf orbiting HD 176535 A,

    Li, Y., Brandt, T. D., Brandt, G. M., An, Q., Franson, K., Dupuy, T. J., Chen, M., Bowens-Rubin, R., Lewis, B. L., Bowler, B. P., Gibbs, A., Kiman, R., Faherty, J., Currie, T., Jensen-Clem, R., Zhang, H., Contreras-Martinez, E., Fitzgerald, M. P., Mazin, B. A., and Millar-Blanchaer, M., “Surveying nearby brown dwarfs with HGCA: direct imaging discovery of...

    work page 2023

  2. [2]

    Astrometric Accelerations as Dynamical Beacons: A Giant Planet Imaged Inside the Debris Disk of the Young Star AF Lep,

    Franson, K., Bowler, B. P., Zhou, Y., Pearce, T. D., Bardalez Gagliuffi, D. C., Biddle, L., Brandt, T. D., Crepp, J. R., Dupuy, T. J., Faherty, J., Jensen-Clem, R., Morgan, M., Sanghi, A., Theissen, C. A., Tran, Q. H., and Wolf, T. A., “Astrometric Accelerations as Dynamical Beacons: A Giant Planet Imaged Inside the Debris Disk of the Young Star AF Lep,”a...

    arXiv 2023

  3. [3]

    Keck/NIRC2 L’-band Imaging of Jovian-mass Accreting Protoplanets around PDS 70,

    Wang, J. J., Ginzburg, S., Ren, B., Wallack, N., Gao, P., Mawet, D., Bond, C. Z., Cetre, S., Wizinowich, P., De Rosa, R. J., Ruane, G., Liu, M. C., Absil, O., Alvarez, C., Baranec, C., Choquet, ´E., Chun, M., Defr` ere, D., Delorme, J.-R., Duchˆ ene, G., Forsberg, P., Ghez, A., Guyon, O., Hall, D. N. B., Huby, E., Jolivet, A., Jensen-Clem, R., Jovanovic, ...

    work page 2020

  4. [4]

    Deep Exploration of Eps Eridani with Keck Ms-band Vortex Coronagraphy and Radial Velocities: Mass and Orbital Parameters of the Giant Exoplanet,

    Mawet, D., Hirsch, L., Lee, E. J., Ruffio, J.-B., Bottom, M., Fulton, B. J., Absil, O., Beichman, C., Bowler, B., Bryan, M., Choquet, E., Ciardi, D., Christiaens, V., Defr` ere, D., Gomez Gonzalez, C. A., Howard, A. W., Huby, E., Isaacson, H., Jensen-Clem, R., Kosiarek, M., Marcy, G., Meshkat, T., Petigura, E., Reggiani, M., Ruane, G., Serabyn, E., Sinuko...

    work page 2019

  5. [5]

    Constraining the Orbit and Mass of epsilon Eridani b with Radial Velocities, Hipparcos IAD-Gaia DR2 Astrometry, and Multiepoch Vortex Coronagraphy Upper Limits,

    Llop-Sayson, J., Wang, J. J., Ruffio, J.-B., Mawet, D., Blunt, S., Absil, O., Bond, C., Brinkman, C., Bowler, B. P., Bottom, M., Chontos, A., Dalba, P. A., Fulton, B. J., Giacalone, S., Hill, M., Hirsch, L. A., Howard, A. W., Isaacson, H., Karlsson, M., Lubin, J., Madurowicz, A., Matthews, K., Morris, E., Perrin, M., Ren, B., Rice, M., Rosenthal, L. J., R...

    work page 2021

  6. [6]

    A Wolf 359 in Sheep’s Clothing: Hunting for Substellar Companions in the Fifth-closest System Using Combined High-contrast Imaging and Radial Velocity Analysis,

    Bowens-Rubin, R., Akana Murphy, J. M., Hinz, P. M., Limbach, M. A., Seifahrt, A., Kiman, R., Salama, M., Mukherjee, S., Brady, M., Carter, A. L., Jensen-Clem, R., van Kooten, M. A. M., Isaacson, H., Kosiarek, M., Bean, J. L., Kasper, D., Luque, R., Stef´ ansson, G., and St¨ urmer, J., “A Wolf 359 in Sheep’s Clothing: Hunting for Substellar Companions in t...

    work page 2023

  7. [7]

    Planet search with the Keck/NIRC2 vortex coronagraph in the M s band for Vega,

    Ren, B. B., Wallack, N. L., Hurt, S. A., Mawet, D., Carter, A. L., Echeverri, D., Llop-Sayson, J., Meshkat, T., Oppenheimer, R., Aguilar, J., Cady, E., Choquet, ´E., Ruane, G., Vasisht, G., and Ygouf, M., “Planet search with the Keck/NIRC2 vortex coronagraph in the M s band for Vega,”aap670, A162 (Feb. 2023)

    work page 2023

  8. [8]

    Characterization of HD 206893 B from Near- to Thermal- infrared,

    Meshkat, T., Gao, P., Lee, E. J., Mawet, D., Choquet, E., Ygouf, M., Patel, R., Ruane, G., Wang, J., Wallack, N., Absil, O., and Beichman, C., “Characterization of HD 206893 B from Near- to Thermal- infrared,”apj917, 62 (Aug. 2021)

    work page 2021

Show all 19 references
  1. [9]

    JWST/NIRCam 4-5µm Imaging of the Giant Planet AF Lep b,

    Franson, K., Balmer, W. O., Bowler, B. P., Pueyo, L., Zhou, Y., Rickman, E., Zhang, Z., Mukherjee, S., Pearce, T. D., Bardalez Gagliuffi, D. C., Biddle, L. I., Brandt, T. D., Bowens-Rubin, R., Crepp, J. R., Davidson, James W., J., Faherty, J., Ginski, C., Horch, E. P., Morgan,...

    2024 arXiv

  2. [10]

    Upgrades to W. M. Keck observatory detector systems,

    Alvarez, C., Kassis, M., Greffe, T., Smith, R., Baril, M., Campbell, R., Gomez, P., Kirby, E., Mawet, D., Roberts, M., Weber, R., Hale, D., Cavalieri, D., Holewczynski, J., Smous, J., Kwok, S., Chan, D., and Dahler, M., “Upgrades to W. M. Keck observatory detector systems,”Ast...

    2023

  3. [11]

    The W. M. Keck Observatory Infrared Vortex Coronagraph and a First Image of HIP 79124 B,

    Serabyn, E., Huby, E., Matthews, K., Mawet, D., Absil, O., Femenia, B., Wizinowich, P., Karlsson, M., Bottom, M., Campbell, R., Carlomagno, B., Defr` ere, D., Delacroix, C., Forsberg, P., Gomez Gonzalez, C., Habraken, S., Jolivet, A., Liewer, K., Lilley, S., Piron, P., Reggian...

    2017

  4. [12]

    On-sky performance of the QACITS pointing control technique with the Keck/NIRC2 vortex coronagraph,

    Huby, E., Bottom, M., Femenia, B., Ngo, H., Mawet, D., Serabyn, E., and Absil, O., “On-sky performance of the QACITS pointing control technique with the Keck/NIRC2 vortex coronagraph,”aap600, A46 (Apr. 2017)

    2017

  5. [13]

    Characterizing the Performance of the NIRC2 Vortex Coronagraph at W. M. Keck Observatory,

    Xuan, W. J., Mawet, D., Ngo, H., Ruane, G., Bailey, V. P., Choquet, ´E., Absil, O., Alvarez, C., Bryan, M., Cook, T., Femen´ ıa Castell´ a, B., Gomez Gonzalez, C., Huby, E., Knutson, H. A., Matthews, K., Ragland, S., Serabyn, E., and Zawol, Z., “Characterizing the Performance ...

    2018

  6. [14]

    Intrinsic and extrinsic absorp- tion of chemical vapor deposition single-crystal diamond from the middle ultraviolet to the far infrared,

    Webster, S., Chen, Y., Turri, G., Bennett, A., Wickham, B., and Bass, M., “Intrinsic and extrinsic absorp- tion of chemical vapor deposition single-crystal diamond from the middle ultraviolet to the far infrared,” Journal of the Optical Society of America B Optical Physics32, ...

    2015

  7. [15]

    L- and M-band annular groove phase mask in lab performance assessment on the vortex optical demonstrator for coronagraphic applications,

    Jolivet, A., Orban de Xivry, G., Huby, E., Piron, P., Catalan, E. V., Habraken, S., Surdej, J., Karlsson, M., and Absil, O., “L- and M-band annular groove phase mask in lab performance assessment on the vortex optical demonstrator for coronagraphic applications,”Journal of Ast...

    2019

  8. [16]

    VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)

    Cutri, R. M., Skrutskie, M. F., van Dyk, S., Beichman, C. A., Carpenter, J. M., Chester, T., Cambresy, L., Evans, T., Fowler, J., Gizis, J., Howard, E., Huchra, J., Jarrett, T., Kopan, E. L., Kirkpatrick, J. D., Light, R. M., Marsh, K. A., McCallon, H., Schneider, S., Stiening...

    2003

  9. [17]

    Modeling the vortex center glow in the ELT/METIS vortex coronagraph,

    Shinde, M., Delacroix, C., Orban de Xivry, G., Absil, O., and van Boekel, R., “Modeling the vortex center glow in the ELT/METIS vortex coronagraph,” in [Modeling, Systems Engineering, and Project Management for Astronomy X], Angeli, G. Z. and Dierickx, P., eds.,Society of Phot...

    2022

  10. [18]

    SCALES on Keck: optical design,

    Kupke, R., Stelter, R. D., Hasan, A., Surya, A., Kain, I., Briesemeister, Z., Li, J., Hinz, P., Skemer, A., Gerard, B., Dillon, D., and Ratliff, C., “SCALES on Keck: optical design,” in [Ground-based and Airborne Instrumentation for Astronomy IX], Evans, C. J., Bryant, J. J., ...

    2022

  11. [19]

    PCA-based approach for subtracting thermal background emission in high-contrast imaging data,

    Hunziker, S., Quanz, S. P., Amara, A., and Meyer, M. R., “PCA-based approach for subtracting thermal background emission in high-contrast imaging data,”aap611, A23 (Mar. 2018)

    2018

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