# Publications

## Requirements for future CMB satellite missions: photometric and band-pass response calibration

Journal of Cosmology and Astroparticle Physics IOP Publishing (2020)

T Ghigna, T Matsumura, G Patanchon, H Ishino, M Hazumi

Current and future Cosmic Microwave Background (CMB) Radiation experiments are targeting the polarized $B$-mode signal. The small amplitude of this signal makes a successful measurement challenging for current technologies. Therefore, very accurate studies to mitigate and control possible systematic effects are vital to achieve a successful observation. An additional challenge is coming from the presence of polarized Galactic foreground signals that contaminate the CMB signal. When they are combined, the foreground signals dominate the polarized CMB signal at almost every relevant frequency. Future experiments, like the LiteBIRD space-borne mission, aim at measuring the CMB $B$-mode signal with high accuracy to measure the tensor-to-scalar ratio $r$ at the $10^{-3}$ level. We present a method to study the photometric calibration requirement needed to minimize the leakage of polarized Galactic foreground signals into CMB polarization maps for a multi-frequency CMB experiment. We applied this method to the LiteBIRD case, and we found precision requirements for the photometric calibration in the range $\sim10^{-4}-2.5\times10^{-3}$ depending on the frequency band. Under the assumption that the detectors are uncorrelated, we found requirements per detector in the range $\sim0.18\times10^{-2}-2.0\times10^{-2}$. Finally, we relate the calibration requirements to the band-pass resolution to define constraints for a few representative band-pass responses: $\Delta\nu\sim0.2-2$ GHz.

## Progress Report on the Large-Scale Polarization Explorer

JOURNAL OF LOW TEMPERATURE PHYSICS Springer Science and Business Media LLC 200 (2020) 374-383

L Lamagna, G Addamo, P Ade, C Baccigalupi, A Baldini, P Battaglia, E Battistelli, A Bau, M Bersanelli, M Biasotti, C Boragno, A Boscaleri, B Caccianiga, S Caprioli, F Cavaliere, F Cei, K Cleary, F Columbro, G Coppi, A Coppolecchia, D Corsini, F Cuttaia, G D'Alessandro, P de Bernardis, G De Gasperis

&#xA9; 2020, Springer Science+Business Media, LLC, part of Springer Nature. The large-scale polarization explorer (LSPE) is a cosmology program for the measurement of large-scale curl-like features (B-modes) in the polarization of the cosmic microwave background. Its goal is to constrain the background of inflationary gravity waves traveling through the universe at the time of matter-radiation decoupling. The two instruments of LSPE are meant to synergically operate by covering a large portion of the northern microwave sky. LSPE/STRIP is a coherent array of receivers planned to be operated from the Teide Observatory in Tenerife, for the control and characterization of the low-frequency polarized signals of galactic origin; LSPE/SWIPE is a balloon-borne bolometric polarimeter based on 330 large throughput multi-moded detectors, designed to measure the CMB polarization at 150 GHz and to monitor the polarized emission by galactic dust above 200&#xA0;GHz. The combined performance and the expected level of systematics mitigation will allow LSPE to constrain primordial B-modes down to a tensor/scalar ratio of 10 - 2. We here report the status of the STRIP pre-commissioning phase and the progress in the characterization of the key subsystems of the SWIPE payload (namely the cryogenic polarization modulation unit and the multi-moded TES pixels) prior to receiver integration.

## The C-Band All-Sky Survey (C-BASS): total intensity point source detection over the northern sky

Monthly Notices of the Royal Astronomical Society Oxford University Press (2020) staa1572

R Grumitt, A Taylor, L Jew, ME Jones, C Dickinson, A Barr, R Cepeda-Arroita, H Chiang, S Harper, H Heilgendorff, JL Jonas, JP Leahy, J Leech, TJ Pearson, MW Peel, ACS Readhead, J Sievers

We present a point source detection algorithm that employs the second order Spherical Mexican Hat Wavelet filter (SMHW2), and use it on C-BASS northern intensity data to produce a catalogue of point sources. The SMHW2 allows us to filter the entire sky at once, avoiding complications from edge effects arising when filtering small sky patches. The algorithm is validated against a set of Monte Carlo simulations, consisting of diffuse emission, instrumental noise, and various point source populations. The simulated source populations are successfully recovered. The SMHW2 detection algorithm is used to produce a $4.76\,\mathrm{GHz}$ northern sky source catalogue in total intensity, containing 1729 sources and covering declinations $\delta\geq-10^{\circ}$. The C-BASS catalogue is matched with the GB6 and PMN catalogues over their common declinations. From this we estimate the $90\%$ completeness level to be approximately $630\,\mathrm{mJy}$, with a corresponding reliability of $95\%$, when applying a Galactic mask covering $20\%$ of the sky. We find the C-BASS and GB6/PMN flux density scales to be consistent with one another to within $3\%$. The absolute positional offsets of C-BASS sources from matched GB6/PMN sources peak at approximately $3.5\,\mathrm{arcmin}$.

## Resolved observations at 31 GHz of spinning dust emissivity variations in rho Oph

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 495 (2020) 3482-3493

C Arce-Tord, M Vidal, S Casassus, M Carcamo, C Dickinson, BS Hensley, R Genova-Santos, JR Bond, ME Jones, ACS Readhead, AC Taylor, JA Zensus

&#xA9; 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. The &#x3C1; Oph molecular cloud is one of the best examples of spinning dust emission, first detected by the cosmic background imager (CBI). Here, we present 4.5 arcmin observations with CBI 2 that confirm 31 GHz emission from &#x3C1; Oph W, the PDR exposed to B-Type star HD 147889, and highlight the absence of signal from S1, the brightest IR nebula in the complex. In order to quantify an association with dust-related emission mechanisms, we calculated correlations at different angular resolutions between the 31 GHz map and proxies for the column density of IR emitters, dust radiance, and optical depth templates. We found that the 31 GHz emission correlates best with the PAH column density tracers, while the correlation with the dust radiance improves when considering emission that is more extended (from the shorter baselines), suggesting that the angular resolution of the observations affects the correlation results. A proxy for the spinning dust emissivity reveals large variations within the complex, with a dynamic range of 25 at 3&#x3C3; and a variation by a factor of at least 23, at 3&#x3C3;, between the peak in &#x3C1; Oph W and the location of S1, which means that environmental factors are responsible for boosting spinning dust emissivities locally.

## Design of a testbed for the study of system interference in space CMB polarimetry

Journal of Low Temperature Physics Springer 199 (2020) 622-630

T Ghigna, T Matsumura, M Hazumi, S Stever, Y Sakurai, N Katayama, A Suzuki, B Westbrook, A Lee

LiteBIRD is a proposed JAXA satellite mission to measure the CMB B-mode polarization with unprecedented sensitivity (σr∼0.001). To achieve this goal, 4676 state-of-the-art TES bolometers will observe the whole sky for 3 years from L2. These detectors, as well as the SQUID readout, are extremely susceptible to EMI and other instrumental disturbances, e.g., static magnetic field and vibration. As a result, careful analysis of the interference between the detector system and the rest of the telescope instruments is essential. This study is particularly important during the early phase of the project, in order to address potential problems before the final assembly of the whole instrument. We report our plan for the preparation of a cryogenic testbed to study the interaction between the detectors and other subsystems, especially a polarization modulator unit consisting of a magnetically rotating half-wave plate. We also present the requirements, current status and preliminary results.

## Updated Design of the CMB Polarization Experiment Satellite LiteBIRD

JOURNAL OF LOW TEMPERATURE PHYSICS Springer Science and Business Media LLC 199 (2020) 1107-1117

H Sugai, P Ade, C Baccigalupi, A Banday, R Banerji, R Barreiro, S Basak, J Beall, S Beckman, M Bersanelli, J Borrill, E Calabrese, F Casas, A Challinor, V Chan, Y Chinone, P Danto, P de Bernardis, T de Haan, M De Petris, C Dickinson, A Duivenvoorden, J-M Duval, K Ebisawa, T Elleflot

&#xA9; 2020, The Author(s). Recent developments of transition-edge sensors (TESs), based on extensive experience in ground-based experiments, have been making the sensor techniques mature enough for their application on future satellite cosmic microwave background (CMB) polarization experiments. LiteBIRD is in the most advanced phase among such future satellites, targeting its launch in Japanese Fiscal Year 2027 (2027FY) with JAXA&#x2019;s H3 rocket. It will accommodate more than 4000 TESs in focal planes of reflective low-frequency and refractive medium-and-high-frequency telescopes in order to detect a signature imprinted on the CMB by the primordial gravitational waves predicted in cosmic inflation. The total wide frequency coverage between 34 and 448&#xA0;GHz enables us to extract such weak spiral polarization patterns through the precise subtraction of our Galaxy&#x2019;s foreground emission by using spectral differences among CMB and foreground signals. Telescopes are cooled down to 5&#xA0;K for suppressing thermal noise and contain polarization modulators with transmissive half-wave plates at individual apertures for separating sky polarization signals from artificial polarization and for mitigating from instrumental 1/f noise. Passive cooling by using V-grooves supports active cooling with mechanical coolers as well as adiabatic demagnetization refrigerators. Sky observations from the second Sun&#x2013;Earth Lagrangian point, L2, are planned for 3&#xA0;years. An international collaboration between Japan, the USA, Canada, and Europe is sharing various roles. In May 2019, the Institute of Space and Astronautical Science, JAXA, selected LiteBIRD as the strategic large mission No. 2.

## Permittivity and permeability of epoxy-magnetite powder composites at microwave frequencies

Journal of Applied Physics 127 (2020)

M Zannoni, T Ghigna, M Jones, A Simonetto

© 2020 Author(s). Radio, millimeter, and sub-millimeter astronomy experiments as well as remote sensing applications often require castable absorbers with well known electromagnetic properties to design and realize calibration targets. In this context, we fabricated and characterized two samples using different ratios of two easily commercially available materials: epoxy (Stycast 2850FT) and magnetite (F e 3 O 4) powder. We performed transmission and reflection measurements from 7 GHz up to 170 GHz with a vector network analyzer equipped with a series of standard horn antennas. Using an empirical model, we analyzed the data to extract complex permittivity and permeability from transmission data; then, we used reflection data to validate the results. In this paper, we present the sample fabrication procedure, analysis method, parameter extraction pipeline, and results for two samples with different epoxy-powder mass ratios.

## The C-Band All-Sky survey (C-BASS)

Proceedings of the 53rd Rencontres de Moriond, Cosmology 2018 ARISF (2018) 137-140

A Taylor

The C-Band All-Sky survey (C-BASS) is an experiment to image the whole sky in intensity and polarization at 5 GHz. The primary aim of C-BASS is to provide low-frequency all-sky maps of the Galactic emission which will enable accurate component separation analysis of both existing and future CMB intensity and polarization imaging surveys. Here we present an overview of the experiment and an update on the current status of observations. We present simulation results showing the expected improvement in the recovery of CMB and foreground signals when including C-BASS data as an additional low-frequency channel, both for intensity and polarization. We also present preliminary results from the northern part of the sky survey.

## The C-Band All-Sky Survey (C-BASS): Simulated parametric fitting in single pixels in total intensity and polarization

Monthly Notices of the Royal Astronomical Society Oxford University Press 490 (2019) 2958-2975

L Jew, AC Taylor, M Jones, A Barr, HC Chiang, C Dickinson, RDP Grumitt, HM Heilgendorff, J Hill-Valler, JL Jonas, JP Leahy, J Leech, TJ Pearson, MW Peel, ACS Readhead, J Sievers

The cosmic microwave background (CMB) B-mode signal is potentially weaker than the diffuse Galactic foregrounds over most of the sky at any frequency. A common method of separating the CMB from these foregrounds is via pixel-based parametric-model fitting. There are not currently enough all-sky maps to fit anything more than the most simple models of the sky. By simulating the emission in seven representative pixels, we demonstrate that the inclusion of a 5 GHz data point allows for more complex models of low-frequency foregrounds to be fitted than at present. It is shown that the inclusion of the C-BASS data will significantly reduce the uncertainties in a number of key parameters in the modelling of both the galactic foregrounds and the CMB. The extra data allow estimates of the synchrotron spectral index to be constrained much more strongly than is presently possible, with corresponding improvements in the accuracy of the recovery of the CMB amplitude. However, we show that to place good limits on models of the synchrotron spectral curvature will require additional low-frequency data.

## Gain Stabilization for Radio Intensity Mapping using a Continuous-Wave Reference Signal

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (0)

AW Pollak, CM Holler, ME Jones, AC Taylor

Stabilizing the gain of a radio astronomy receiver is of great importance for sensitive radio intensity mapping. In this paper we discuss a stabilization method using a continuous-wave reference signal injected into the signal chain and tracked in a single channel of the spectrometer to correct for the gain variations of the receiver. This method depends on the fact that gain fluctuations of the receiver are strongly correlated across the frequency band, which we can show is the case for our experimental setup. This method is especially suited for receivers with a digital back-end with high spectral resolution and moderate dynamic range. The sensitivity of the receiver is unaltered except for one lost frequency channel. We present experimental results using a new 4-8.5 GHz receiver with a digital back-end that shows substantial reduction of the 1/ f noise and the 1/ f knee frequency.

## The C-Band All-Sky Survey (C-BASS): constraining diffuse Galactic radio emission in the North Celestial Pole region

Monthly Notices of the Royal Astronomical Society Oxford University Press 485 (2019) 2844-2860

C Dickinson, A Barr, HC Chiang, C Copley, RDP Grumitt, HM Heilgendorff, LRP Jew, JL Jonas, ME Jones, JP Leahy, J Leech, EM Leitch, SJC Muchovej, TJ Pearson, MW Peel, ACS Readhead, J Sievers, MA Stevenson, A Taylor

The C-Band All-Sky Survey (C-BASS) is a high sensitivity all-sky radio survey at an angular resolution of 45 arcmin and a frequency of 4.7 GHz. We present a total intensity map of the North Celestial Pole (NCP) region of sky, above declination &gt;+80°, which is limited by source confusion at a level of ≈0.6 mK rms. We apply the template-fitting (cross-correlation) technique to WMAP and Planck data, using the C-BASS map as the synchrotron template, to investigate the contribution of diffuse foreground emission at frequencies ∼20–40 GHz. We quantify the anomalous microwave emission (AME) that is correlated with far-infrared dust emission. The AME amplitude does not change significantly (⁠&lt;10 per cent⁠) when using the higher frequency C-BASS 4.7 GHz template instead of the traditional Haslam 408 MHz map as a tracer of synchrotron radiation. We measure template coefficients of 9.93 ± 0.35 and 9.52±0.34 K per unit τ353 when using the Haslam and C-BASS synchrotron templates, respectively. The AME contributes 55±2μK rms at 22.8 GHz and accounts for ≈60 per cent of the total foreground emission. Our results show that a harder (flatter spectrum) component of synchrotron emission is not dominant at frequencies ≳5 GHz; the best-fitting synchrotron temperature spectral index is β = −2.91 ± 0.04 from 4.7 to 22.8 GHz and β = −2.85 ± 0.14 from 22.8 to 44.1 GHz. Free–free emission is weak, contributing ≈7μK rms (⁠≈7 per cent⁠) at 22.8 GHz. The best explanation for the AME is still electric dipole emission from small spinning dust grains.

## The C-Band All-Sky Survey (C-BASS): Digital backend for the northern survey

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2019)

MA Stevenson, TJ Pearson, ME Jones, CJ Copley, C Dickinson, JJ John, OG King, SJC Muchovej, AC Taylor

## The C-Band All-Sky Survey (C-BASS): design and capabilities

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 480 (2018) 3224-3242

ME Jones, AC Taylor, M Aich, CJ Copley, HC Chiang, RJ Davis, C Dickinson, RDP Grumitt, Y Hafez, HM Heilgendorff, CM Holler, MO Irfan, LRP Jew, JJ John, J Jonas, OG King, JP Leahy, J Leech, EM Leitch, SJC Muchovej, TJ Pearson, MW Peel, ACS Readhead, J Sievers, MA Stevenson, J Zuntz

## Concept design of the LiteBIRD satellite for CMB B-mode polarization

SPACE TELESCOPES AND INSTRUMENTATION 2018: OPTICAL, INFRARED, AND MILLIMETER WAVE 10698 (2018) ARTN 106981Y

Y Sekimoto, P Ade, K Arnold, J Aumont, J Austermann, C Baccigalupi, A Banday, R Banerji, S Basak, S Beckman, M Bersanelli, J Borrill, F Boulanger, ML Brown, M Bucher, E Calabrese, FJ Casas, A Challinor, Y Chinone, F Columbro, A Cukierman, D Curtis, P de Bernardis, M de Petris, M Dobbs, T Dotani, L Duband, J Duval, A Ducout, K Ebisawa, T Elleot, H Eriksen, J Errard, R Flauger, C Franceschet, U Fuskeland, K Ganga, JR Gao, T Ghigna, J Grain, A Gruppuso, N Halverson, P Hargrave, T Hasebe, M Hasegawa, M Hattori, M Hazumi, S Henrot-Versille, C Hill, Y Hirota, E Hivon, DT Hoang, J Hubmayr, K Ichiki, H Imada, H Ishino, G Jaehnig, H Kanai, S Kashima, Y Kataoka, N Katayama, T Kawasaki, R Keskitalo, A Kibayashi, T Kikuchi, K Kimura, T Kisner, Y Kobayashi, N Kogiso, K Kohri, E Komatsu, K Komatsu, K Konishi, N Krachmalnicoff, CL Kuo, N Kurinsky, A Kushino, L Lamagna, AT Lee, E Linder, B Maffei, M Maki, A Mangilli, E Martinez-Gonzalez, S Masi, T Matsumura, A Mennella, Y Minami, K Mistuda, D Molinari, L Montier, G Morgante, B Mot, Y Murata, A Murphy, M Nagai, R Nagata, S Nakamura, T Namikawa, P Natoli, T Nishibori, H Nishino, F Noviello, C O'Sullivan, H Ochi, H Ogawa, H Ogawa, H Ohsaki, I Ohta, N Okada, G Patanchon, F Piacentini, G Pisano, G Polenta, D Poletti, G Puglisi, C Raum, S Realini, M Remazeilles, H Sakurai, Y Sakurai, G Savini, B Sherwin, K Shinozaki, M Shiraishi, G Signorelli, G Smecher, R Stompor, H Sugai, S Sugiyama, A Suzuki, J Suzuki, R Takaku, H Takakura, S Takakura, E Taylor, Y Terao, KL Thompson, B Thorne, M Tomasi, H Tomida, N Trappe, M Tristram, M Tsuji, M Tsujimoto, S Uozumi, S Utsunomiya, N Vittorio, N Watanabe, I Wehus, B Westbrook, B Winter, R Yamamoto, NY Yamasaki, M Yanagisawa, T Yoshida, J Yumoto, M Zannoni, A Zonca

## The STRIP instrument of the Large Scale Polarization Explorer: microwave eyes to map the Galactic polarized foregrounds

MILLIMETER, SUBMILLIMETER, AND FAR-INFRARED DETECTORS AND INSTRUMENTATION FOR ASTRONOMY IX 10708 (2018) ARTN 107081G

C Franceschet, S Realini, A Mennella, G Addamo, A Bau, PM Battaglia, M Bersanelli, B Caccianiga, S Caprioli, F Cavaliere, KA Cleary, F Cuttaia, F Del Torto, V Fafone, Z Farooqui, RTG Santos, TC Gaier, M Gervasi, T Ghigna, F Incardona, S Iovenitti, M Jones, P Kangaslahti, R Mainini, D Maino, M Maris, P Mena, R Molina, G Morgante, A Passerini, MDR Perez-de-Taoro, OA Peverini, F Pezzotta, C Pincella, N Reyes, A Rocchi, JAR Martin, M Sandri, S Sartor, M Soria, V Tapia, L Terenzi, M Tomasi, E Tommasi, DM Vigano, F Villa, G Virone, A Volpe, B Watkins, A Zacchei, M Zannoni

## Design and development of a polarization modulator unit based on a continuous rotating half-wave plate for LiteBIRD

MILLIMETER, SUBMILLIMETER, AND FAR-INFRARED DETECTORS AND INSTRUMENTATION FOR ASTRONOMY IX 10708 (2018) ARTN 107080E

Y Sakurai, T Matsumura, N Katayama, H Imada, K Komatsu, H Kanai, R Takaku, S Shugiyama, T Ghigna, T Iida, H Sugai, H Ohsaki, Y Terao, T Shimomura, K Konishi, H Sakurai, J Yumoto, M Maki, J Suzuki, H Ishino, S Nakamura, A Kusaka, C Hill, M Hazumi, H Kataza, S Utsunomiya, R Yamamoto, M Tashiro, Y Terada

## A compact quad-ridge orthogonal mode transducer with wide operational bandwidth

IEEE Antennas and Wireless Propagation Letters Institute of Electrical and Electronics Engineers 17 (2018) 422-425

A Pollak, ME Jones

We present the design and the measured performance of a compact quad-ridge orthomode transducer (OMT) operating in C-band with more than 100% fractional bandwidth. The OMT comprises two sets of identical orthogonal ridges mounted in a circular waveguide. The profile of these ridges was optimised to reduce significantly the transition length, while retaining the wide operational bandwidth of the quad-ridge OMT. In this letter, we show that the optimised compact OMT has better than -15dB return loss with the cross-polarisation well below -40dB in the designated 4.0-8.5GHz band.

## The state-of-play of Anomalous Microwave Emission (AME) research

New Astronomy Reviews Elsevier (2018)

BT Draine, R Génova-Santos, Harper, B Hensley, JR Hill-Valler, T Hoang, FP Israel, L Jew, A Lazarian, JP Leahy, J Leech, CH López-Carabello, I McDonald, EJ Murphy, T Onaka, R Paladini, MW Peel, Y Perrott, F Poidevin, ACS Readhead, J-A Rubiño-Martín, AC Taylor, CT Tibbs, M Todorovic, M Vidal

Anomalous Microwave Emission (AME) is a component of diffuse Galactic radiation observed at frequencies in the range ≈10–60 GHz. AME was first detected in 1996 and recognised as an additional component of emission in 1997. Since then, AME has been observed by a range of experiments and in a variety of environments. AME is spatially correlated with far-IR thermal dust emission but cannot be explained by synchrotron or free–free emission mechanisms, and is far in excess of the emission contributed by thermal dust emission with the powerlaw opacity consistent with the observed emission at sub-mm wavelengths. Polarization observations have shown that AME is very weakly polarized ( ≲ 1 %). The most natural explanation for AME is rotational emission from ultra-small dust grains (“spinning dust”), first postulated in 1957. Magnetic dipole radiation from thermal fluctuations in the magnetization of magnetic grain materials may also be contributing to the AME, particularly at higher frequencies ( ≳ 50 GHz). AME is also an important foreground for Cosmic Microwave Background analyses. This paper presents a review and the current state-of-play in AME research, which was discussed in an AME workshop held at ESTEC, The Netherlands, June 2016.

## The Low Frequency Receivers for SKA1-Low: Design and Verification

2017 XXXIIND GENERAL ASSEMBLY AND SCIENTIFIC SYMPOSIUM OF THE INTERNATIONAL UNION OF RADIO SCIENCE (URSI GASS) (2017)

P Benthem, M Gerbers, JGB de Vaate, S Wijnholds, J Bast, T Booler, T Colgate, B Crosse, D Emrich, P Hall, B Juswardy, D Kenney, F Schlagenhaufer, M Sokolowski, A Sutinjo, D Ung, R Wayth, A Williams, M Alderighi, P Bolli, G Comoretto, A Mattana, J Monari, G Naldi, F Perini, G Pupillo, S Rusticelli, M Schiaffino, F Schilliro, A Aminei, R Chiello, M Jones, J Baker, R Bennett, R Halsall, G Kaligeridou, M Roberts, H Schnetler, J Abraham, EDL Acedo, A Faulkner, N Razavi-Ghods, D Cutajar, A DeMarco, A Magro, KZ Adami, IEEE

## A Herschel Space Observatory Spectral Line Survey of Local Luminous Infrared Galaxies from 194 to 671 Microns

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES 230 (2017) ARTN 1

N Lu, Y Zhao, T Diaz-Santos, C Kevin Xu, Y Gao, L Armus, KG Isaak, JM Mazzarella, PP van der Werf, PN Appleton, V Charmandaris, AS Evans, J Howell, K Iwasawa, J Leech, S Lord, AO Petric, GC Privon, DB Sanders, B Schulz, JA Surace