| nasa/ipac extragalactic database | NED | 22 | 16 | 1.000437 | 9904241,9904322,etc |
| point spread function | PSF | 294 | 15 | 2.005145 | 9904058,9904426,etc |
| star formation rate | SFR | 106 | 15 | 1.001777 | 9904340,9904428,etc |
| cold dark matter | CDM | 166 | 13 | 2.002048 | 9904282,9904340,etc |
| active galactic nucleus | AGN | 282 | 12 | 2.002785 | 9904322,9904076,etc |
| cosmic microwave background | CMB | 291 | 12 | 1.004763 | 9904235,9904228,etc |
| gamma ray burst | GRB | 420 | 12 | 1.003438 | 9904262,9904181,etc |
| interstellar medium | ISM | 79 | 11 | 1.00131 | 9904056,9904002,etc |
| very large array | VLA | 76 | 10 | 1.001022 | 9904421,9904248,etc |
| spectral energy distribution | SED | 82 | 9 | 1.002013 | 9904057,9904416,etc |
| hubble space telescope | HST | 63 | 9 | 1.00087 | 9904044,9904032,etc |
| initial mass function | IMF | 155 | 9 | 1.001525 | 9904134,9904291,etc |
| rossi x ray timing explorer | RXTE | 69 | 8 | 2.001348 | 9904111,9904293,etc |
| low mass x ray binary | LMXB | 34 | 8 | 1.000656 | 9904212,9904110,etc |
| asymptotic giant branch | AGB | 74 | 8 | 2.002197 | 9904400,9904291,etc |
| large magellanic cloud | LMC | 100 | 8 | 2.002592 | 9904032,9904368,etc |
| red giant branch | RGB | 94 | 8 | 2.001717 | 9904010,9904387,etc |
| color magnitude diagram | CMD | 140 | 7 | 1.001761 | 9904212,9904183,etc |
| proportional counter array | PCA | 99 | 7 | 2.001334 | 9904391,9904123,etc |
| luminosity function | LF | 55 | 6 | 1.000523 | 9904340,9904183,etc |
| full width at half maximum | FWHM | 19 | 6 | 1.000278 | 9904002,9904249,etc |
| far infrared | FIR | 55 | 6 | 2.002016 | 9904225,9904099,etc |
| quasi periodic oscillation | QPO | 287 | 5 | 2.004934 | 9904111,9904110,etc |
| broad line region | BLR | 79 | 5 | 2.002261 | 9904054,9904370,etc |
| supernova remnant | SNR | 89 | 5 | 2.002165 | 9904243,9904056,etc |
| sunyaev zel'dovich | SZ | 171 | 5 | 1.00435 | 9904235,9904168,etc |
| supernova | SN | 308 | 5 | 2.009398 | 9904225,9904121,etc |
| smoothed particle hydrodynamics | SPH | 65 | 5 | 2.003674 | 9904386,9904145,etc |
| wide field camera | WFC | 14 | 4 | 1.001897 | 9904385,9904114,etc |
| neutron star | NS | 94 | 4 | 1.005833 | 9904293,9904331,etc |
| wide field planetary camera 2 | WFPC2 | 64 | 4 | 2.000657 | 9904032,9904114,etc |
| planetary nebula | PN | 409 | 4 | 2.005438 | 9904032,9904202,etc |
| inner lindblad resonance | ILR | 32 | 4 | 1.000553 | 9904428,9904206,etc |
| cosmic background radiation | CBR | 70 | 4 | 2.002965 | 9904049,9904367,etc |
| lyon meudon extragalactic database | LEDA | 22 | 4 | 1.000495 | 9904326,9904259,etc |
| massive compact halo object | Macho | 59 | 4 | 2.001905 | 9904291,9904064,etc |
| ultraviolet | UV | 25 | 4 | 2.000977 | 9904137,9904294,etc |
| signal to noise ratio | SNR | 18 | 4 | 1.000264 | 9904238,9904187,etc |
| big bang nucleosynthesis | BBN | 46 | 4 | 2.003514 | 9904052,9904220,etc |
| all sky monitor | ASM | 26 | 4 | 1.001894 | 9904286,9904123,etc |
| ultraluminous infrared galaxy | ULIRG | 100 | 4 | 2.003185 | 9904277,9904126,etc |
| equation of state | EOS | 97 | 4 | 2.003054 | 9904028,9904211,etc |
| extragalactic background light | EBL | 23 | 4 | 2.001503 | 9904292,9904179,etc |
| main sequence | MS | 86 | 4 | 2.001188 | 9904387,9904219,etc |
| ministry for university and research | MURST | 4 | 4 | 1.000051 | 9904101,9904203,etc |
| equivalent width | eV | 64 | 3 | 1.003419 | 9904058,9904249,etc |
| position angle | PA | 30 | 3 | 2.001283 | 9904421,9904271,etc |
| small magellanic cloud | SMC | 31 | 3 | 2.001811 | 9904012,9904032,etc |
| position sensitive proportional counter | PSPC | 14 | 3 | 1.000285 | 9904012,9904375,etc |
| planetary nebulae | PN | 175 | 3 | 2.010624 | 9904400,9904291,etc |
| near infrared | NIR | 114 | 3 | 2.002813 | 9904054,9904202,etc |
| intergalactic medium | IGM | 40 | 3 | 2.00122 | 9904340,9904291,etc |
| x ray background | XRB | 51 | 3 | 2.00173 | 9904340,9904341,etc |
| space telescope imaging spectrograph | STIS | 42 | 3 | 1.004165 | 9904032,9904161,etc |
| diffuse ionized gas | DIG | 105 | 3 | 1.002997 | 9904428,9904154,etc |
| gamma ray bursts | GRB | 64 | 3 | 1.002369 | 9904038,9904216,etc |
| power spectral density | PSD | 30 | 3 | 2.000867 | 9904304,9904123,etc |
| singular isothermal sphere | SIS | 11 | 3 | 2.000417 | 9904426,9904028,etc |
| equivalent widths | EW | 128 | 3 | 2.002898 | 9904426,9904134,etc |
| advection dominated accretion flow | ADAF | 55 | 3 | 1.002084 | 9904100,9904123,etc |
| kolmogorov smirnov | KS | 3 | 3 | 1.00003 | 9904374,9904149,etc |
| infrared space observatory | ISO | 42 | 3 | 2.002183 | 9904136,9904176,etc |
| hubble deep field | HDF | 30 | 3 | 2.000678 | 9904014,9904179,etc |
| ryle telescope | RT | 59 | 3 | 2.003068 | 9904168,9904165,etc |
| infrared | IR | 52 | 3 | 2.001111 | 9904099,9904112,etc |
| narrow field instrument | NFI | 9 | 3 | 1.002733 | 9904286,9904169,etc |
| planetary camera | PC | 44 | 3 | 2.001251 | 9904106,9904247,etc |
| compact steep spectrum | CSS | 18 | 3 | 1.001424 | 9904106,9904141,etc |
| compton gamma ray observatory | CGRO | 4 | 3 | 1.000235 | 9904039,9904123,etc |
| period luminosity | PL | 26 | 3 | 2.000812 | 9904027,9904360,etc |
| intracluster medium | ICM | 55 | 3 | 1.004298 | 9904386,9904429,etc |
| high energy x ray timing experiment | HEXTE | 61 | 3 | 2.000505 | 9904123,9904244,etc |
| proportional counter unit | PCU | 6 | 3 | 1.000205 | 9904123,9904222,etc |
| horizontal branch | HB | 138 | 3 | 2.005383 | 9904387,9904377,etc |