#spectroscopy — Public Fediverse posts

In 2003, Paul Eilers published a paper titled “A Perfect Smoother” [1], re-implementing and extending early ideas published by Whittaker in the 1920s [2].

The method is based on a penalised least square approach, also called Tikhonov regularization (also called ridge regression!) and is a very general approach to deal with smoothing noisy data, overcoming some of the limitations of the Savitzky-Golay method.

Read more on my recent blog post 👇

https://nirpyresearch.com/whittaker-smoothing/

[1] Paul H. C. Eilers (2003). A Perfect Smoother, Anal. Chem. 75 (14): 3631–3636.
[2] E. T. Whittaker (1922). On a New Method of Graduation, Proceedings of the Edinburgh Mathematical Society, 41: 63 – 75.

#spectroscopy #smoothing #DataProcessing #ImageProcessing #Python #MachineLearning #Regression

My old post and web app about light spectrum is the second one to reach 1000 views on my website. Congrats to myself !

https://baillehachepascal.dev/2022/reflectance_editor.php

#computergraphics #rendering #webapp #spectroscopy #light #color #povray

A Stray Rocket Hit the Moon at 5,400 mph. Telescopes Read the Crash's Chemistry

Like and share if you enjoyed this.

https://1ban.news/falcon9-moon-impact-spectroscopy/

#1ban #falcon9 #moon #impact #spectroscopy #science

Over the last few years, we've been shifting our thinking of many "abiotic" carbonate minerals. That gives us another set of tools to look for signs of life in other planets with spectroscopic tools.

Link: https://www.sciencedirect.com/science/article/pii/S0019103526003283

#biosignatures #Spectroscopy

RE: https://aus.social/@danielpelliccia/116843445917856343

Still time to register for the next Nirpy Webinar presented by Dr Mercedes Bertotto.

"Bridging Model Validation and Analytical Validation in Spectroscopy: The Role of the Accuracy Profile"

When: Tomorrow, July 15th, 2026, 16:00 CET

#Spectroscopy #Machine_learning #MachineLearning #NIR #NearInfrared

OK, here's a sample selection method that doubles as training/test splitting method.

If you've ever trained a machine learning model from physical data, you know that acquiring calibration samples may be costly and laborious.

If you have a cheaper proxy, for instance optical or near-infrared #spectroscopy as a not-so-random example, you can use that proxy to pre-select the samples to be used for calibration.

And if you already have all of your samples, you can still use this method to select the training set.

The algorithm was proposed by G Puchwein many years ago. For some reason, I couldn't find a #Python implementation of it, so here it is 👇

https://nirpyresearch.com/sample-selection-puchwein-algorithm/
#MachineLearning #NIR #DataScience

Astronomers Discover Mysterious Compound on Pluto and Titan

📰 Original title: Mysterious Compound Detected on Pluto and Titan

🤖 IA: It's not clickbait ✅
👥 Users: It's not clickbait ✅

View full AI summary https://en.killbait.com/astronomers-discover-mysterious-compound-on-pluto-and-titan.html?utm_source=mastodon_world&utm_medium=social&utm_campaign=killbait.mastodon_world

#science #spectroscopy #planetaryscience #astrochemistry

📣 Wednesday 15th July, at 16:00 CET, I'll be hosting a webinar presented by Dr Mercedes Bertotto (Wittenborg University):

"Bridging Model Validation and Analytical Validation in Spectroscopy: The Role of the Accuracy Profile"

The idea behind the talk is to highlight that validation of #chemometrics models alone is often not sufficient. In addition to classical model validation approaches, analytical validation, traditionally used in analytical chemistry and laboratory testing, should also be applied in chemometrics and #spectroscopy workflows to ensure true method performance and reliability.

Registration is free at this link👇
https://events.humanitix.com/nirpy-webinar-2

#MachineLearning

`By performing spectroscopy and super-resolution microscopy at liquid helium temperature, we shed light on the spectral and spatial features of the adsorbed species. Our results pave the way for investigations in solid-state physics, where angstrom spatial resolution can be combined with high-resolution laser spectroscopy.`

http://dx.doi.org/10.1126/science.aeg5014

#spectroscopy #adsorption #nanotechnology

Weekly Update from the Open Journal of Astrophysics 20/06/2026

It’s Saturday again so it’s time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further three papers, bringing the number in Volume 9 (2026) to 126 and the total so far published by OJAp up to 574.

I will continue to include the posts made on our Mastodon account (on Fediscience); these announcements also show the DOI for each paper.

The first paper to report this week, published on Monday 15th June, is “SN 2025adpq: A Type Ia supernova in a collisional ring formed during a major galaxy merger” by Brendan O’Connor (Carnegie Mellon University, USA) and 18 others based in the USA, Germany and Australia. The study reports the discovery of a Type Ia supernova, SN 2025adpq, within a collisional ring formed by a major galaxy merger., offset from the nucleus of the primary galaxy. It is published in the folder Astrophysics of Galaxies.

The overlay for this paper is here

You can find the officially accepted version on arXiv here and the announcement on Fediverse here:

https://fediscience.org/@OJ_Astro/116753183446523072

The second paper for this week, published on Tuesday June 16th in the folder Astrophysics of Galaxies is “The Colors of Ices: Measuring ice column density through photometry” by Adam Ginsburg (U. Florida, USA) and ten others based in the USA, Germany and Spain. This study demonstrates that JWST photometry can identify and quantify interstellar ices, using new open-source models, interstellar ices, finding significant abundance in non-star-forming gas, suggesting many avenues for further research.

The overlay looks like this:

The official version of the paper can be found on arXiv here and the Fediverse announcement here:

https://fediscience.org/@OJ_Astro/116758595971333611

The third paper of the week, published on Wednesday 17th June in the folder Cosmology and Nongalactic Astrophysics is “The Non-Gaussian Weak-Lensing Likelihood: A Multivariate Copula Construction and Impact on Cosmological Constraints” by Veronika Oehl and Tilman Tröster (both of ETH Zurich, Switzerland). This study presents a framework for computing non-Gaussian likelihoods for correlation functions, particularly useful in large-scale weak-lensing surveys. It suggests Gaussian likelihoods are sufficient for stage-IV surveys.

The overlay for this one is here:

The final, accepted version can be found on arXiv here and the Mastodon announcement is here:

https://fediscience.org/@OJ_Astro/116764509657843733

The fourth and final paper of the week, also ublished on Wednesday 17th June but in the folder Astrophysics of Galaxies, is “Black Hole Feedback, Galaxy Quenching and Outflows at Cosmic Dawn: Analysis of the SEEDZ Simulations” by Lewis R. Prole (Maynooth University, Ireland) and 15 others based in Ireland, Germany, USA and UK. The study analyzes the growth and feedback effects of massive black holes in SEEDZ simulations, suggesting that black hole feedback, not nearby supernovae or gas exhaustion, limits initial growth.

The overlay is here:

The final, accepted version can be found on arXiv here and the Mastodon announcement is here:

https://fediscience.org/@OJ_Astro/116764428903842241

And that concludes this week’s update. It has been a slow week on the publishing front, but the main reason is that we have a big backlog of papers accepted but waiting for the authors to put their final versions on arXiv and we can’t do anything about that! I’ll do another update next Saturday.

Weekly Update from the Open Journal of Astrophysics 13/06/2026

It’s Saturday again so it’s time for another update of activity at the Open Journal of Astrophysics. Since the last update we have published a further three papers, bringing the number in Volume 9 (2026) to 122 and the total so far published by OJAp up to 570.

I will continue to include the posts made on our Mastodon account (on Fediscience); these announcements also show the DOI for each paper.

The first paper to report this week, published on Thursday 11th June, is “Dancing Streams In Merging Halos: Stellar Streams in a MW–LMC-like merger” by (all based in the USA): Sachi Weerasooriya (Carnegie Observatories), Tjitske Starkenburg (Northwestern U.), Emily C. Cunningham (Columbia U.) & Kathryn V. Johnston (Flatiron Institute). This article explores how galaxy mergers, like the Milky Way-Large Magellanic Cloud merger, significantly alter the properties and structures of stellar streams, challenging the recovery of their initial orbits. It is in the folder marked Astrophysics of Galaxies.

The overlay for this paper is here

You can find the officially accepted version on arXiv here and the announcement on Fediverse here:

https://fediscience.org/@OJ_Astro/116730200889106529

The second paper for this week, also published on Thursday 11th June but in the folder Cosmology and Nongalactic Astrophysics is “X-SORTER (X-ray Survey Of meRging clusTErs in Redmapper): X-ray and Spectroscopic Characterization of 12 Optically Selected Galaxy Cluster Merger Candidates” by Christopher Hopp, David Wittman, Rodrigo Stancioli, Zhuoran Gao & Faik Bouhrik (UC Davis) and Scott Adler (Rochester), all based in the USA. The X-SORTER program identifies merging galaxy clusters to study dark matter interactions, using optical indicators and X-ray observations. This method efficiently identifies active clusters suitable for detailed dark matter studies.

The overlay for this one looks like this:

The official version of the paper can be found on arXiv here and the Fediverse announcement here:

https://fediscience.org/@OJ_Astro/116730279994960097

The third and final paper of the week, published on Friday 12th June in the folder Earth and Planetary Astrophysics, is “JCMT Constraints on the Early-Time HCN and CO Emission and HCN Temporal Evolution of 3I/ATLAS” by Jason T. Hinkle (U. Illinois, USA) and 6 others based in the USA and Chile. This article presents observations of the third Interstellar Object, 3I/ATLAS, providing early sub-mm constraints on its activity. The findings suggest a steeper production rate slope than typical Solar System comets.

The overlay for this one is here:

The final, accepted version can be found on arXiv here and the Mastodon announcement is here:

https://fediscience.org/@OJ_Astro/116735805179724489

And that concludes this week’s update. It has been a slow week on the publishing front, but the main reason is that we have a big backlog of papers accepted but waiting for the authors to put their final versions on arXiv and we can’t do anything about that! I’ll do another update next Saturday.

I'm presenting a webinar on
"Class modelling and outlier detection in NIR spectroscopy"

We have two sessions scheduled
🔸 Session 1 (best for the Americas): Jun 16th, 06:00 - 07:00 (UTC+10)
🔸 Session 2 (best for EMEA - APAC): Jun 16th, 18:00 - 19:00 (UTC+10)

Registration is free, but spots are limited.

Details and abstract are on the registration page 👇
https://www.trybooking.com/DMSTO

#NIR #spectroscopy #NearInfrared #Chemometrics #Python #MachineLearning

🌍☀️ Scientists at #ArizonaState and #Caltech used the #JWST to produce the first weather report for WASP-94A b, a gas giant 700 light-years from #Earth.

The #planet has two different #weather sides: a morning edge with #clouds made of vaporized #rock and an almost cloud-free evening edge, driven by temperature differences and powerful winds.

👉 https://www.scientificamerican.com/article/jwst-sees-partly-cloudy-skies-on-a-distant-giant-exoplanet/

#exoplanet #space #nasa #astronomy #wasp94ab #science #telescope #atmosphere #spectroscopy

Invitation to join tomorrow's FREE online BeilsteinTalk “Probing nanostructures atom by atom: An advanced electron microscopy study” with Nasim Alem, The Pennsylvania State University 🇺🇸.

📅 May 21, 2026
🕒 3–4 pm CEST
Register for FREE 🔗 https://www.beilstein-institut.de/en/talks/nanotechnology-probing-nanostructures-atom-by-atom-an-advanced-electron-microscopy-study/?M=y

#ScanningTunnelingMicroscopy #spectroscopy #TransmissionElectronMicroscopy #TEM #AtomicForceMicroscopy #AFM #BeilsteinTalks

The revised analysis does not fully rule out #Europa plumes, but it substantially weakens the original #HST #Lyα evidence. After accounting for Europa’s extended #hydrogen #exosphere and improved background modeling, the previously reported localized excess emission is no longer statistically compelling.

📝 https://doi.org/10.1051/0004-6361/202659406

🧵2/2

#PlanetaryScience #SpacePhysics #Spectroscopy #Jupiter

🌖🔭Roth, Retherford, Saur et al revise their 2014 paper: In a reanalysis of 23 #HST/ #STIS #Lyα observations, the authors revisit & revise their earlier #Europa water plume interpretation.

With improved disk positioning & inclusion of a #hydrogen-#exosphere model, the previously reported localized Lyα excess becomes substantially less significant & may be consistent with noise. The data instead robustly support a persistent atomic H exosphere.

🧵1/n

#PlanetaryScience #SpacePhysics #Spectroscopy

Coming up next week: Join the online #BeilsteinTalk "Probing nanostructures atom by atom: An advanced electron microscopy study" with Nasim Alem, The Pennsylvania State University 🇺🇸.

📅 May 21, 2026
🕒 3–4 pm CEST

Register for FREE 🔗 https://www.beilstein-institut.de/en/talks/nanotechnology-probing-nanostructures-atom-by-atom-an-advanced-electron-microscopy-study/?M=y

#ScanningTunnelingMicroscopy #spectroscopy #TransmissionElectronMicroscopy #TEM #AtomicForceMicroscopy #AFM #BeilsteinTalks

Making an astronomer portrait with a juicy rainbow roll 🌈

#linocut #printmaking #sciart #spectroscopy #histsci

Save the date 📅 May 21, 2026 🕒 3–4 pm CEST

Online #BeilsteinTalk "Probing nanostructures atom by atom: An advanced electron microscopy study" with Nasim Alem, The Pennsylvania State University 🇺🇸.

Register for FREE 🔗 https://www.beilstein-institut.de/en/talks/nanotechnology-probing-nanostructures-atom-by-atom-an-advanced-electron-microscopy-study/?M=y

#ScanningTunnelingMicroscopy #spectroscopy #TransmissionElectronMicroscopy #TEM #AtomicForceMicroscopy #AFM #BeilsteinTalks

📣 I'm planning to organize an online series of webinars/workshops, focused on #chemometrics and #MachineLearning for #spectroscopy (using #Python )

I'd like it to be beginner-friendly and informal.

🆓 Free registration

🏛️ Tutorial and research talks (including guest speakers and workshop sessions)

📅 Monthly or fortnightly schedule

💻 Fully online

If it sound like you may be interested, please read more and register your interest here
https://nirpyresearch.com/nirpy-webinars/

#Webinar

If your #spectroscopy dataset is small, deterministic data subdivision into training and test sets may be the way to go 🔬

The SPXY algorithm is an extension of the Kennard-Stone method that selects training samples to maximize coverage of both spectra (X) and response variable (Y) at the same time.

Here's a primer, with a #Python implementation for #NIR spectroscopy.

https://nirpyresearch.com/spxy-algorithm/

#Chemometrics #MachineLearning

New instance, new #introduction

#science #physics
since 2021 working on
#fiberlinks #frequency #time #transfer #reference #quantum #metrology
before that on
#biophysics #raman #spectroscopy #microscopy #biofilm #bacteria #protein #microplastics

#programming & #computing
#python (#fortran #mathematica )
#linux (not quite but almost still a newbie)
#freesoftware

Other interests:
#plants #cats #sciencefiction #fantasy #reading #writing #audiobooks #asiandramas #unplugbigtech #diday

A personal highlight for me was of course the full-scale model of the #HubbleSpaceTelescope ❤️🔭

#Hubble #Smithsonian #HST #Ganymede #Spectroscopy #STIS #Aurora #Jupiter #Museum #SpacePhysics #PlasmaPhysics #Plasma #Space #Astronomy

Scale Dependence In Remotely Sensed Biodiversity: Leveraging Continental-Scale Imaging Spectroscopy From The National Ecological Observatory Network [spatial analysis]
--
https://doi.org/10.1002/rse2.70068 <-- shared paper
--
https://doi.org/10.1038/s41559-022-01702-5 <-- shared paper
--
#spectraldiversity #spectroscopy #spatialscale #US #NEON #NationalEcologicalObservatoryNetwork #species #ecology #humanimpacts #remotesensing #biodiversity #earthobservation #GIS #spatial #mapping #scale #scale #diversity #metrics #ecosystems #spectral #richness #scaledependency #principalcompoenent #divergence #spatialanalysis #raster #topography #climate #geomorphology #regression #geostatistics #vegetation #plant #area #region #largescale #continent #forest #tree

Timing And Style Of Tectonic Assembly And Exhumation Of The Mchugh Complex Within The Chugach-Kodiak Accretionary Wedge, Alaska
--
https://doi.org/10.1029/2025TC009004 <-- shared paper
--
https://discoveryalert.com.au/chugach-prince-william-terrain-geology-alaska-2025 <-- shared technical article
--
[this paper is WAY over my head in terms of the nuance of structural geology, but still fascinating; further, I have to say: these are TRULY gorgeous, well-designed & presented, and useful geologic maps, cross-sections, annotated photographs and other visualisations (I am jealous of that level of skill, in the BEST of ways!)]
#geology #structuralgeology #fieldwork #geologic #mapping #KenaiPeninsula #McHughComplex #tectonics #underplating #faulting #subduction #erosion #Exhumation #ChugachKodiak #AccretionaryWedge #Alaska #coast #coastal #mineralogy #transects #crosssections #model #modeling #sampling #spectroscopy #accretionary #accretionarymargin #plateboundary #trench #interpretation #peneplanation #forearc

Dumb NMR question. Why don't we see splitting from 35Cl or 37Cl in the solvent signal when we run either 1H or 13C NMR? Is it being decoupled as with {1H}13C or does it have something to do with the gyromagnetic ratio or???? #NMR #coupling #decoupling #spectroscopy #chemistry #chemchat #help

"The Soil and Water Management and Crop Nutrition Laboratory of the Joint FAO/IAEA Centre of Nuclear Techniques is looking for a Consultant for the SoilFER Soil Spectroscopy position (TAL-NAFA20260120-001). This role (in the frame of the SoilFER project) is suitable for individuals with good hands-on experience in infrared spectroscopy for soil property monitoring." #SoilScience #Spectroscopy #ScienceJob #GetFediHired

https://iaea.taleo.net/careersection/ex/jobdetail.ftl?job=TAL-NAFA20260120-001&tz=GMT-08%3A00&tzname=America%2FLos_Angeles

I learnt about the "entropy of the derivative" or delentropy from the paper linked.

The idea is that the standard formula for information entropy doesn't distinguish between permutations. The entropy formula −∑p(x)logp(x) depends on p(x) which, absent any extra information about a signal, is estimated by the histogram of that signal.

Now, if we do a random permutation of the values of the signal, the histogram doesn't change, so the entropy doesn't change. To find an 'entropy metric' that accounts for that we need to go to the second order, calculating the entropy of the signal derivative.

The delentropy is sensitive to the actual shape of a signal or spectrum, not only the distribution of its values.

https://arxiv.org/abs/1609.01117

#physics #SignalProcessing #spectroscopy