NIKA2 Homepage

The New IRAM KID Array 2 (NIKA2) is a dual-band camera operating with three frequency-multiplexed kilopixels arrays of Lumped Element Kinetic Inductance Detectors (LEKID) cooled at 150mK. NIKA2 is designed to observe simultaneously the intensity at 1.15 and 2.0 mm. In addition, it allows for polarisation observations at 1.15 mm. NIKA2 is built by an international consortium, led by the Institute Neel (Grenoble, France).

Contents

NIKA2 Homepage

NIKA2 in the web:

News

In March 2025, NIKA2 was upgraded (cf. Call for proposals for the winter semester 2025). New 1mm KID arrays were installed, the dichroic was exchanged, various filters have been exchanged. Commissioning is still ongoing as of 15-July 2025. New bandpasses have been measured. A report is in preparation.
Polarimetry at 1mm has been commissioned in 2022 and observations of the B-FUN large polarimetry program have started.
Since October 2019, the PIIC software for the reduction of NIKA2 data is available for download together with an extensive, regularly updated tutorial (see the PIIC dedicated page).
After a phase of upgrades, tests, and commissioning, NIKA2 has been offered to the astronomy community for total power observations since October 2017.
Since October 2015, NIKA2 is installed at the IRAM 30m telescope.

Overview

Preliminary NIKA2+ properties (after the upgrade in March 2025)

Band	Number of KIDs	Wavelength	Bandwidth	NEFD	HPBW	FoV
NIKA2 2 mm/150 GHz	616	2.00 mm	125-170 GHz	9 ± 1 mJy*s^1/2	17.6"	6.5'
NIKA2 1 mm/260 GHz	2x1140	1.15 mm	TBD	20 ± 3 mJy*s^1/2	11.1"	6.5'

NIKA2 properties (valid till February 2025)

Band	Number of KIDs	Wavelength	Bandwidth	NEFD	HPBW	FoV
NIKA2 2 mm/150 GHz	616	2.00 mm	125-170 GHz	9 ± 1 mJy*s^1/2	17.6"	6.5'
NIKA2 1 mm/260 GHz	2x1140	1.15 mm	240-280 GHz	30 ± 3 mJy*s^1/2	11.1"	6.5'

Comments: The half-power beam widths and the NEFDs are taken from Perotto et al. 2020. The NEFDs are extrapolated to a sky opacity of 0 and 90 deg. elevation.

NIKA2 observing time estimator

A Python script to estimate observing times is available together with a document describing the approach and giving examples. Please find it here.

PIIC data reduction software

The PIIC software for the reduction of NIKA2 total-power and polarimetry data is available for download together with an extensive, regularly updated tutorial (see the PIIC dedicated page).

The five Guaranteed Time Large Programs

Four Large Programs (LPs) for NIKA2 in guaranteed time (GT) were submitted to the Program Committee for the deadline in September 2016, and one for the March 2017 deadline. All 5 have been rated high by the PC and have been observed. Here, we provide the proposal abstracts together with the list of sources and map sizes. The three large programs in Phase I have started observations in October 2017. while the Phase II large program on nearby galaxies, 160-16, has started in the summer semester 2019 and the B-Fun NIKA2Pol project has started in the winter semester 2021/22. Till end of November 2024, the four GT LPs in total power (GASTON, N2CLS, NIKA2SZ, IMEGIN) are still "fenced" against new continuum 2mm/1mm mapping projects at the 30m or NOEMA. The B-FUN GT LP in polarimetry is yet ongoing and continues to be fenced.

Source list
- NIKA2-GT-LPs-08feb2022.pdf
- NIKA2-GT-LPs-08feb2022.xls
Phase I
- Galactic Star Formation with NIKA2 - GASTON (122-16) PI is Nicolas Peretto. Abstract: The IMF is a fundamental global output of the star formation process, and the question of its origin and universality has been a long-standing open issue. While the base of the IMF (0.1 to 1 Msun) may result from Jeans-like fragmentation of interstellar filaments, the problem of how the most extreme stellar objects (brown dwarfs, intermediate- and high-mass stars) build up their masses remains unsettled. The high-sensitivity and fast mapping capability of the NIKA2 camera offer the unique opportunity to detect large populations of low-brightness sources, and probe star-forming regions as never before. We propose to use this new instrument to: i. perform a complete survey of pre-brown-dwarf cores in two nearby star-forming regions, ii. map the intertwined populations of interstellar filaments and intermediate to high-mass cores within rich galactic plane star-forming regions; iii. use the dual band capability of NIKA2 at 1.2mm and 2mm to constrain the dust properties in a broad range of environments and reduce mass uncertainties by a factor of 3. Altogether, these observations will provide new insight on the earliest stages of star formation across both ends of the stellar IMF.
- The NIKA2 Cosmological Legacy Survey (N2CLS) (192-16) PIs: Guilaine Lagache, Alexandre Beelen, Nicolas Ponthieu Abstract: Using 300h of the NIKA2 Guaranteed Time, we will map the star formation at high redshift in two of the most popular fields. N2CLS will reach for the first time the confusion noise at the 30m, in 160 square arcminutes in GOODS-N. In COSMOS, N2CLS sensitivity will at least match or outperform the sensitivity of the S2CLS survey at 850 microns on 0.5 square degree. N2CLS will detect hundreds of dust-obscured optically-faint galaxies during their major episodes of formation in the early universe. It will fully open a new window on the faint and high-redshift dusty Universe and answer the outstanding issue of whether dusty star-formation contributes to early galaxy evolution. It will uniquely probe the transition at z~3-4 of the cosmic star-formation history between the predominantly unobscured growth in the early Universe and the obscured star formation, driven by the build-up of the most massive galaxies during the peak of cosmic assembly. The availability of this uniquely large sample of mm-selected galaxies with superb supporting multi-wavelength data will provide the opportunity to address the history of star formation, dust production and the growth of large-scale structures.
- High-resolution tSZ observations of a large sample of clusters of galaxies (NIKA2SZ) (199-16) PIs: Frédéric Mayet, Laurence Perotto Homepage: NIKA2LPSZ Abstract: The development of precision cosmology with clusters of galaxies requires high angular resolution observations to extend the understanding of galaxy clusters towards high redshift. The NIKA2 camera at the IRAM 30 m telescope is the only instrument currently in operation that is suited for this kind of observations, given its resolution, sensitivity and dual-band observation capability. We intend to observe a large sample of clusters of galaxies at high redshift (0.5 < z < 0.9), selected from the Planck and ACT catalogs. We have formed a representative cluster sample for redshift evolution and cosmological studies, with a homogeneous coverage in cluster mass as reconstructed from the integrated Compton parameter. We will use the SZ-dedicated pipeline that we have developed for the SZ observation with the NIKA camera. Our primary objective is to produce unprecedented high-quality deliverables (tSZ maps and pressure profiles) for all clusters of the sample. NIKA2 data will be complemented with ancillary data including X-ray, optical and radio observations. The full dataset will lead to significant improvements on the use of clusters of galaxies to draw cosmological constraints.
Phase II
- Interpreting the Millimetre Emission of Galaxies with IRAM and NIKA (IMEGIN) (160-16) PI is Suzanne Madden Abstract: The mm part of the spectrum is one of the least explored parts of a galaxy’s spectral energy distribution (SED), yet it contains emission from three fundamentally important physical processes. These processes are thermal emission from dust, free-free emission from ionized gas and synchrotron emission from charged particles moving in the galactic magnetic field. We are proposing to use the NIKA2 camera to observe a sample of 22 nearby galaxies that also have considerable ancillary data across the SED from the radio to the ultra-violet. We will investigate the dust emissivity, the relationship between the three physical processes and their relation to star formation and the gas-to-dust ratio. As the sample galaxies are of large angular size we will be able to carry out this project in a spatially resolved way and hence investigate the different environments found within galaxies.
- Probing the B-Field in star-forming Filaments Using NIKA2-Pol (B-FUN) (015-17) PI: Philippe Andre Abstract: Recent Herschel and Planck observations of Galactic interstellar clouds support a paradigm of star formation in which magnetized filaments play a central role. Herschel results indicate that most cores/stars form in dense, supercritical filaments of ~0.1 pc width, and Planck polarization data suggest that the formation and evolution of these filaments is largely controlled by magnetic fields. The low resolution of Planck polarization data is however insufficient to probe individual cores along filaments and understand the role of B fields in filament evolution and fragmentation. To make decisive progress in this area, we propose a 1.2 mm polarimetric imaging survey with NIKA2-POL of ~8 nearby star-forming filaments spanning a range of line masses from marginally supercritical to highly supercritical. The proposed observations will constrain the role of magnetic fields in channeling matter from filaments to prestellar cores and will determine whether the B field remains roughly perpendicular to the filaments, as observed by Planck on larger scales, or becomes more parallel to the filaments in their dense interior, which would have profound implications for core formation.

Publications

Astronomical papers:
- NIKA2
  - Berta et al., 2025, A panchromatic view of N2CLS GOODS-N: The evolution of the dust cosmic density since z∼7, A&A, 696, A193 ADS
  - Andreon et al., 2025, The uncommon intracluster medium features of the first massive clusters selected independently of their baryon content, MNRAS, 536, 3466 ADS
  - Ejlali et al., 2024, Interpreting Millimeter Emission from IMEGIN galaxies NGC 2146 and NGC 2976, A&A, 693, A88 ADS
  - Adam et al., 2024, The XXL Survey. LI. Pressure profile and YSZ − M scaling relation in three low-mass galaxy clusters at z ∼ 1 observed with NIKA2, A&A, 684A, 18, ADS
  - Bing et al. 2024, Faint mm NIKA2 dusty star-forming galaxies: Finding the high-redshift population, A&A, 683A, 232, ADS
  - Rigby et al. 2024, The dynamic centres of infrared-dark clouds and the formation of cores, MNRAS, 528, 1172 ADS
  - Beuther et al. 2023, Density distributions, magnetic field structures and fragmentation in high-mass star formation, A&A, 682A, 81 ArXiv ADS
  - Bing et al. 2023, NIKA2 Cosmological Legacy Survey: Survey Description and Galaxy Number Counts, A&A, 677A, 66 ArXiv ADS
  - Katsioli et al. 2023, NGC891 seen at millimeter wavelengths, A&A, 679, A7 ArXiv ADS
  - Scibelli et al. 2023, 3D Radiative Transfer Modelling and Virial Analysis of Starless Cores in the B10 Region of the Taurus Molecular Cloud, MNRAS, 521, 4579 ArXiv, ADS
  - Sai et al. 2022, Which Part of Dense Cores Feeds Material to Protostars? The Case of L1489 IRS, A&A, 925, 12 ADS
  - Muñoz-Echeverría et al. 2022, Multi-probe analysis of the galaxy cluster CL J1226.9+3332: Hydrostatic mass and hydrostatic-to-lensing bias,A&A, 671A, 28, ADS
  - Rose et al. 2022, The variability of brightest cluster galaxies at high radio frequencies, MNRAS, 509, 2869 ADS
  - Lestrade et al. 2022, Candidate cosmic filament in the GJ526 field, mapped with the NIKA2 camera, A&A, 667, A23 ADS
  - Ferragamo et al. 2022, Comparison of hydrostatic and lensing cluster mass estimates: A pilot study in MACS J0647.7+7015, ADS
  - Gianfagna et al. 2021, Exploring the hydrostatic mass bias in MUSIC clusters: application to the NIKA2 mock sample, MNRAS, 502, 5115 ADS
  - Rigby et al. 2021, GASTON: Galactic Star Formation with NIKA2. Evidence for the mass growth of star-forming clumps, ArXiv MNRAS, 502, 4576
  - Luppe et al. 2021, Observability of dusty debris discs around M-stars, MNRAS, 499, 3932 ADS
  - Ricci et al. 2020, The XXL Survey. XLIV. Sunyaev-Zel'dovich mapping of a low-mass cluster at z ∼ 1: a multi-wavelength approach, A&A, 642, A126 ADS
  - Keruzore et al. 2020, Exploiting NIKA2/XMM-Newton imaging synergy for intermediate-mass high-z galaxy clusters within the NIKA2 SZ large program. Observations of ACT-CL J0215.4+0030 at z ˜ 0.9, A&A, 644, A93 ADS
  - Torne et al. 2020, Detection of the magnetar XTE J1810-197 at 150 and 260 GHz with the NIKA2 kinetic inductance detector camera, A&A, 640, L2 ADS
  - Ruppin et al. 2020, Unveiling the Merger Dynamics of the Most Massive MaDCoWS Cluster at z = 1.2 from a Multiwavelength Mapping of Its Intracluster Medium Properties, ApJ
  - Ruppin et al. 2018, First Sunyaev-Zel'dovich mapping with NIKA2: implication of cluster substructures on the pressure profile and mass estimate, A&A, 2018, 26, 615, astro-ph
- NIKA2 conference proceedings
  - Conference proceedings of mm Universe 2023 - Observing the Universe at mm Wavelengths
  - Conference proceedings of mm Universe 2021 @ NIKA2 - Observing the mm Universe with the NIKA2 Camera
  - Conference proceedings of mm Universe 2019 @ NIKA2 - Observing the mm Universe with the NIKA2 Camera
  - Bonnefoy et al. 2024, Microwave spectra of the leading and trailing hemispheres of Iapetus, ADS ICARUS
  - Bonnefoy et al. 2019, Millimetric thermal emission from the two faces of Iapetus, ADS
- NIKA
  - Sicilia-Aguilar et al. 2019, IRAM and Gaia views of multi-episodic star formation in IC 1396A The origin and dynamics of the Class 0 protostar at the edge of an HII region, A&A (622, 118) ADS
  - Adam et al. 2018, Sub-structure and merger detection in resolved NIKA Sunyaev-Zel'dovich images of distant clusters, A&A (614, A118)
  - Romero et al. 2018, A multi-instrument non-parametric reconstruction of the electron pressure profile in the galaxy cluster CLJ1226.9+3332, A&A (613, 39)
  - Rigby, A., Peretto, N., et al. 2018, A NIKA view of two star-forming infrared dark clouds: Dust emissivity variations and mass concentration, astro-ph A&A, 615, A18
  - Ritacco, A., Macías Pérez, J.-F., Ponthieu, N. et al. 2018, NIKA 150 GHz polarization observations of the Crab nebula and its spectral energy distribution, A&A, 616, A35
  - Adam et al. 2017, Mapping the hot gas temperature in galaxy clusters using X-ray and Sunyaev-Zel'dovich imaging, A&A, 606, 64 ADS
  - Bracco et al. 2017, Probing changes of dust properties along a chain of solar-type prestellar and protostellar cores in Taurus with NIKA, A&A, 604, 52 ADS
  - Ritacco, A., Ponthieu, N, Catalano, A., et al., 2017, Polarimetry at millimeter wavelengths with the NIKA camera: calibration and performance, A&A, 599, A34, ADS
  - Chacon-Tanarro et al. 2017, Search for grain growth towards the center of L1544, A&A, 606, A142 ADS
  - Ruppin, F., Adam, R., Comis, B., et al. 2016, Non parametric deprojection of NIKA SZ observations: pressure distribution in the Planck-discovered cluster PSZ1 G045.85+57.71, A&A, in press ADS
  - Adam, R., Bartalucci, I., Pratt, G. W., et al. 2016, Mapping the kinetic Sunyaev-Zel'dovich effect toward MACS J0717.5+3745 with NIKA, A&A, ADS
  - Adam, R., Comis, B., Bartalucci, I., et al. 2016, High angular resolution Sunyaev-Zel'dovich observations of MACS J1423.8+2404 with NIKA: Multiwavelength analysis, A&A, 586, 122 ADS
  - Adam, R., Comis, B., Macias-Perez, J.-F., et al., 2015, Pressure distribution of the high-redshift cluster of galaxies CL J1226.9+3332 with NIKA, A&A, 576, A12 ADS
  - Adam, R., Comis, B., Macias-Perez, J.-F, et al., 2014, First observation of the thermal Sunyaev-Zel'dovich effect with kinetic inductance detectors, A&A, 569, 66 ADS
- NIKA related papers
  - Aumont, J., Macías Pérez, J.-F., Ritacco, A., Ponthieu, N., Mangilli, A., 2018, Absolute calibration of the polarisation angle for future CMB B-mode experiments from current and future measurements of the Crab nebula, (submitted to A&A) arxiv
  - Chastenet et al., 2022, SOFIA/HAWC+ observations of the Crab Nebula: dust properties from polarized emission, MNRAS, 516,4229 ADS
Instrument/detectors papers:
- NIKA2
  - Perotto et al. 2020, Calibration and Performance of the NIKA2 camera at the IRAM 30-meter Telescope, arxiv A&A
  - Adam et al. 2018, The NIKA2 large field-of-view millimeter continuum camera for the 30-m IRAM telescope, arxiv A&A
  - Catalano et al. 2016, The NIKA2 commissioning campaign: performance and first results, arxiv
  - Calvo et al. 2016, The NIKA2 instrument, a dual-band kilopixel KID array for millimetric astronomy, arxiv
- NIKA
  - Bourrion et al. 2016, NIKEL_AMC: Readout electronics for the NIKA2 experiment, arxiv
  - Ritacco et al. 2016, First polarised light with the NIKA camera, JLTP, Volume 184, Issue 3-4, pp. 724-732, 08/2016 arxiv
  - Goupy et al. 2016, Microfabrication technology for large LEKID arrays : from NIKA2 to future applications, arxiv
  - Monfardini et al. 2014, Latest NIKA Results and the NIKA-2 Project, JLTP 176, 787, arxiv
  - Catalano et al. 2014, Performance and calibration of the NIKA camera at the IRAM 30 m telescope, A&A 569, A9, arxiv
  - Calvo et al. 2013, Improved mm-wave photometry for kinetic inductance detectors, A&A, 551, L12 ADS
  - Bourrion et al. 2012, NIKEL: Electronics and data acquisition for kilopixels kinetic inductance camera, Journal of Instrumentation, 7, 07, pp. 7014. arXiv
  - Monfardini et al. 2011, A Dual-band Millimeter-wave Kinetic Inductance Camera for the IRAM 30 m Telescope, ApJS, 194, 2, article id. 24. arXiv
  - Internal list of technical papers
Ph.D. thesis:
- Aurélien Bideaud (2007-2010) - NEEL - Supervisors: A. Benoit and F.-X. Desert - Development of a camera for millimeter-wave radioastronomy.
- Markus Roesch (2010 - 2013) - IRAM - Supervisors: K. Schuster and M. Siegel - Development of lumped element kinetic inductance detectors for mm-wave astronomy at the IRAM 30m telescope.
- Antonio D’Addabbo (2011 - 2014) - NEEL - Supervisors: A. Monfardini and P. de Bernardis - Applications of Kinetic Inductance Detectors to Astronomy and Particle Physics.
- Rémi Adam (2012-2015) - LPSC - Advisors: J.F. Macías-Pérez and F.X. Désert - Observation of galaxy clusters via the Sunyaev-Zel'dovich effect and the polarization of the cosmic microwave background (in French).
- Grégoire Coiffard (2012 - 2015) - IRAM - Supervisor: K. Schuster - Development of kinetic inductance detectors for millimeter astronomy and related problems in material science and process technology.
- Alessia Ritacco (2013-2016) - LPSC - Advisors: J.F. Macías-Pérez, Alessandro Monfardini, Andrea Catalan and Nicolas Ponthieu - Polarimetry at millimeter wavelengths with the instruments NIKA and NIKA2.
- Florian Ruppin (2016 - 2018) - LPSC - Supervisor: F. Mayet - Cosmology from Sunyaev-Zel’dovich observations of galaxy clusters with the NIKA2.
- Shibo Shu (2017 - 2019) - IRAM - Supervisors: K. Schuster and E. Driessen - Large format LEKID arrays for millimeter-wave astronomy.
- Aina Andrianasolo (2017 - 2019) - IPAG - Supervisors: F.-X. Desert and N. Ponthieu - Measuring the sky polarization with KIDS on the ground with NIKA2 and preparing satellite observations.
- Florian Kéruzoré (2019 - 2021) - LPSC - Supervisors: F. Mayet - Cosmologie à partir des observations Sunyaev-Zeldovich d’amas de galaxies avec NIKA2.
- Miren Muñoz Echevarría (2021 - 2023) - LPSC - Supervisors: J.F. Macías-Pérez - Cosmologie multi-longueur d'onde avec les amas de galaxies.
- Corentin Hanser (2022 - 2024) - LPSC - Supervisors: L. Perotto - Cosmologie avec les amas de galaxies dans l'expérience NIKA2.
Talks:
- Alessia Ritacco, November 2016, Polarimetry at Millimeter wavelengths with NIKA and NIKA2 ritacco-seminar-nika2-nov2016.pdf
- Many more talks in the dedicated private wiki table
NIKA2 publications list maintained at IPAG

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Information for Observers & Technical Documentation

Observations
- Pool observations provides information on the observing modes offered for NIKA2 and examples of the scripts that you must prepare to observe your project.
- Observing session provides an example of a typical session with NIKA2 at the 30m telescope.
- Pointing sources and calibrators provides a list of pointing sources and calibrators.
- Polarimetric observations provides information for observers on how to conduct observations. In addition, it lists how to change between total power mode to polarimetry mode and vice versa.
Data reduction
- PIIC software.
- IDL pipeline
Cryostat & Electronics & PIMP
Network
- Computer Network, M.Calvo, June-2017
- Remote network access to nika2-a computer
Acquisition and tuning

Science runs (October 2017 - February 2025)

See the progress of observations in the Pool data base and in TAPAS. Both databases are synchronized and can be used to write/read a logsheet.

Current Semester: Winter 2024

7-14 January 2025 - w24 Pool #1 [= Cryo Run 82, 70^th of NIKA2]
- Observers and staff at the telescope
- Daily Reports
14-21 January 2025 - w24 Pool #2 [= Cryo Run 82, 70^th of NIKA2]
- Observers and staff at the telescope
- Daily Reports
28 Jan.-3 Feb. 2025 - w24 Pool #3 [= Cryo Run 82, 70^th of NIKA2]
- Observers and staff at the telescope
- Daily Reports
10-18 February 2025 - w24 Pool #4 [= Cryo Run 83, 71^st of NIKA2]
- Observers and staff at the telescope
- Daily Reports
18-25 February 2025 - w24 Pool #5 [= Cryo Run 83, 71^st of NIKA2]
- Observers and staff at the telescope
- Daily Reports

Previous Semester: Summer 2024

22-28 October 2024 - s24 Pool preliminaries [= Cryo Run 80, 68^th of NIKA2]
- Daily Reports
29 Oct.-5 Nov. 2024 - s24 Pool #1 [= Cryo Run 80, 68^th of NIKA2]
- Observers and staff at the telescope
- Daily Reports
5-12 November 2024 - s24 Pool #2 [= Cryo Run 80, 68^th of NIKA2]
- Observers and staff at the telescope
- Daily Reports
19-26 November 2024 - s24 Pool #3 [= Cryo Run 81, 69^th of NIKA2]
- Observers and staff at the telescope
- Daily Reports
26 Nov-3 Dec. 2024 - s24 Pool #4 [= Cryo Run 81, 69^th of NIKA2]
- Observers and staff at the telescope
- Daily Reports

Older Semesters

Science Runs Winter 2023
No science observations in Summer 2023 due to 30m telescope upgrade (Cryo Run 76, 64^th of NIKA2 for testing & telescope commissioning)
Science Runs Winter 2022
Science Runs Summer 2022
Science Runs Winter 2021
Science Runs Summer 2021
Science Runs Winter 2020
Science Runs Summer 2020
Science Runs Winter 2019
Science Runs Summer 2019
Science Runs Winter 2018
Science Runs Summer 2018
Science Runs Winter 2017
Previously accepted projects in open time.